Diocletian AD 284-305. BI Aurellianianus. Roman Imperial. NGC XF Silvering.Diocletian(/da.klin/;Latin:Gaius Aurelius Valerius Diocletianus,Ancient Greek:,romanized:Diokletians; 242/245 311/312), nicknamed "Jovius" (Latin:Iovius), wasRoman emperorfrom 284 until his abdication in 305. He was bornGaius Valerius Dioclesto a family of low status in theRoman provinceofDalmatia. Diocles rose through the ranks of the military early in his career, eventually becoming acavalrycommander for the army of EmperorCarus. After the deaths of Carus and his sonNumerianon a campaign in Persia, Diocles was proclaimed emperor by the troops, taking the name Diocletianus. The title was also claimed by Carus's surviving son,Carinus, but Diocletian defeated him in theBattle of the Margus.Diocletian's reign stabilized the empire and ended theCrisis of the Third Century. He appointed fellow officerMaximianasAugustus, co-emperor, in 286. Diocletian reigned in theEastern Empire, and Maximian reigned in theWestern Empire. Diocletian delegated further on 1 March 293, appointingGaleriusandConstantiusas junior colleagues (each with the titleCaesar), under himself and Maximian respectively. Under theTetrarchy, or "rule of four", each tetrarch would rule over a quarter-division of the empire. Diocletian secured the empire's borders and purged it of all threats to his power. He defeated theSarmatiansandCarpiduring several campaigns between 285 and 299, theAlamanniin 288, and usurpers inEgyptbetween 297 and 298. Galerius, aided by Diocletian, campaigned successfully againstSassanid Persia, the empire's traditional enemy. In 299, he sacked their capital,Ctesiphon. Diocletian led the subsequent negotiations and achieved a lasting and favorable peace. Diocletian separated and enlarged the empire's civil and military services and reorganized the empire's provincial divisions, establishing the largest and mostbureaucraticgovernment in the history of the empire. He established new administrative centres inNicomedia,Mediolanum,Sirmium, andTrevorum, closer to the empire's frontiers than the traditional capital at Rome. Building on third-century trends towardsabsolutism, he styled himself an autocrat, elevating himself above the empire's masses with imposing forms of court ceremonies and architecture. Bureaucratic and military growth, constant campaigning, and construction projects increased the state's expenditures and necessitated a comprehensive tax reform. From at least 297 on, imperial taxation was standardized, made more equitable, and levied at generally higher rates. Not all of Diocletian's plans were successful: theEdict on Maximum Prices(301), his attempt to curb inflation viaprice controls, was counterproductive and quickly ignored. Although effective while he ruled, Diocletian'stetrarchic system collapsedafter his abdication under the competing dynastic claims ofMaxentiusand Constantine, sons of Maximian and Constantius respectively. TheDiocletianic Persecution(303312), the empire's last, largest, and bloodiest officialpersecution of Christianity, failed to eliminate Christianity in the empire. After 324, Christianity became the empire's preferred religion underConstantine. Despite these failures and challenges, Diocletian's reforms fundamentally changed the structure of the Roman imperial government and helped stabilize the empire economically and militarily, enabling the empire to remain essentially intact for another 150 years despite being near the brink of collapse in Diocletian's youth. Weakened by illness, Diocletian left the imperial office on 1 May 305, becoming the first Roman emperor to abdicate the position voluntarily. He lived out his retirement inhis palace on the Dalmatian coast, tending to his vegetable gardens. His palace eventually became the core of the modern-day city ofSplitin Croatia. Early life Panorama of amphitheatre inSalona Diocletian was born inDalmatia, probably at or near the town ofSalona(modernSolin,Croatia), to which he retired later in life. His name at birth was Diocles (in full, Gaius Valerius Diocles),[3]possibly derived from Dioclea, the name of both his mother and her supposedplace of birth.[4]Diocletian's official birthday was 22 December, and his year of birth has been estimated at between 242 and 245 based on a statement that he was aged 68 at death (alongside other evidence).His parents were of low status;Eutropiusrecords "that he is said by most writers to have been the son of a scribe, but by some to have been a freedman of a senator called Anulinus." The first forty years of his life are mostly obscure.Diocletian was considered anIllyricianus(Illyrian) who had been schooled and promoted byAurelian.The 12th-centuryByzantinechroniclerJoannes Zonarasstates that he wasDuxMoesiae,a commander of forces on the lowerDanube.The often-unreliableHistoria Augustastates that he served inGaul, but this is not corroborated by other sources and is ignored by modern historians.The first time Diocletian's whereabouts are accurately established was in 282 when the EmperorCarusmade him commander of theProtectores domestici, the elite cavalry force directly attached to the Imperial household. This post earned him the honor of a consulship in 283. Death of Numerian Carus's death, amid a successful war with Persia and in mysterious circumstances he was believed to have been struck by lightning or killed by Persian soldiers left his sonsNumerianand Carinus as the newAugusti. Carinus quickly made his way to Rome from his post in Gaul and arrived there by January 284, becoming the legitimate Emperor in the West. Numerian lingered in the East.The Roman withdrawal from Persia was orderly and unopposed.TheSassanidkingBahram IIcould not field an army against them as he was still struggling to establish his authority. By March 284, Numerian had only reachedEmesa (Homs)inSyria; by November, only Asia Minor.In Emesa he was apparently still alive and in good health: he issued the only extantrescriptin his name there,but after he left the city, his staff, including the prefect (Numerian's father-in-law and the dominant influence in his entourage)Aper, reported that he suffered from an inflammation of the eyes. He traveled in a closed coach from then on. When the army reachedBithynia, some of the soldiers smelled an odor emanating from the coach.[They opened its curtains and found Numerian dead.BothEutropiusandAurelius Victordescribe Numerian's death as an assassination. Aper officially broke the news inNicomedia(zmit) in November.Numerian's generals and tribunes called a council for the succession, and chose Diocles as Emperor,in spite of Aper's attempts to garner support.On 20 November 284, the army of the east gathered on a hill 5 kilometres (3.1mi) outside Nicomedia. The army unanimously saluted Diocles as their newAugustus, and he accepted the purple imperial vestments. He raised his sword to the light of the sun and swore an oath disclaiming responsibility for Numerian's death. He asserted that Aper had killed Numerian and concealed it.In full view of the army, Diocles drew his sword and killed Aper.According to theHistoria Augusta, he quoted fromVirgilwhile doing so.Soon after Aper's death, Diocles changed his name to the more Latinate "Diocletianus" in full, Gaius Valerius Diocletianus. Conflict with Carinus Head ofCarinusat theCentrale Montemartini After his accession, Diocletian andLucius Caesonius Bassuswere named as consuls and assumed thefascesin place of Carinus and Numerian.Bassus was a member of asenatorialfamily fromCampania, a formerconsuland proconsul of Africa, chosen by Probus for signal distinction.He was skilled in areas of government where Diocletian presumably had no experience.Diocletian's elevation of Bassus symbolized his rejection of Carinus' government in Rome, his refusal to accept second-tier status to any other emperor, and his willingness to continue the long-standing collaboration between the empire's senatorial and military aristocracies.It also tied his success to that of the Senate, whose support he would need in his advance on Rome. Diocletian was not the only challenger to Carinus' rule; the usurperJulianus, Carinus'corrector Venetiae, took control of northernItalyandPannoniaafter Diocletian's accession.Julianus minted coins from Siscia (Sisak, Croatia) declaring himself emperor and promising freedom. This aided Diocletian in his portrayal of Carinus as a cruel and oppressive tyrant. Julianus' forces were weak, and were handily dispersed when Carinus' armies moved from Britain to northern Italy. As the leader of the united East, Diocletian was clearly the greater threat.Over the winter of 28485, Diocletian advanced west across theBalkans. In the spring, some time before the end of May,his armies met Carinus' across the river Margus (Great Morava) inMoesia. In modern accounts, the site has been located between the Mons Aureus (Seone, west ofSmederevo) andViminacium,near modernBelgrade, Serbia. Despite having a stronger, more powerful army, Carinus held the weaker position. His rule was unpopular, and it was later alleged that he had mistreated the Senate and seduced his officers' wives.It is possible thatFlavius Constantius, the governor of Dalmatia and Diocletian's associate in the household guard, had already defected to Diocletian in the early spring.When theBattle of the Margusbegan, Carinus' prefectAristobulusalso defected.In the course of the battle, Carinus was killed by his own men. Following Diocletian's victory, both the western and the eastern armies acclaimed him as Emperor.Diocletian exacted an oath of allegiance from the defeated army and departed for Italy. Early rule Aureusof Diocletian, mintedc.288 Diocletian may have become involved in battles against theQuadiandMarcomanniimmediately after the Battle of the Margus. He eventually made his way to northern Italy and made an imperial government, but it is not known whether he visited Rome at this time.There is a contemporary issue of coins suggestive of an imperialadventus(arrival) for the city,but some modern historians state that Diocletian avoided the city, as the city and its Senate were no longer politically relevant to the affairs of the empire and needed to be taught as much. Diocletian dated his reign from his elevation by the army, not his ratification by the Senate,following the practice established by Carus, who had declared the Senate's ratification a useless formality.However, Diocletian offered proof of his deference towards the Senate by retaining Aristobulus as ordinary consul and colleague for 285 (one of the few instances during the Late Empire in which an emperor admitted aprivatusas his colleague)and by creating senior senators Vettius Aquilinus and Junius Maximus ordinary consuls for the following year for Maximus, it was his second consulship. If Diocletian did enter Rome shortly after his accession, he did not stay long;he is attested back in the Balkans by 2 November 285, on campaign against theSarmatians. Head of Diocletian at theNational Museum of Serbia Diocletian replaced theprefectof Rome with his consular colleague Bassus. Most officials who had served under Carinus, however, retained their offices under Diocletian.In an act ofclementiadenoted by the epitomator ofAurelius Victoras unusual, Diocletian did not kill or depose Carinus's traitorous praetorian prefect and consulAristobulus, but confirmed him in both roles.He later gave him the proconsulate of Africa and the post of urban prefect for 295.The other figures who retained their offices might have also betrayed Carinus. Maximian made Caesar The assassinations ofAurelianand Probus demonstrated that sole rulership was dangerous to the stability of the empire.[24]Conflict boiled in every province, from Gaul to Syria, Egypt to the lower Danube. It was too much for one person to control, and Diocletian needed a lieutenant.At some time in 285 atMediolanum(Milan),Diocletian raised his fellow-officerMaximianto the office ofCaesar, making him his effective co-ruler. The concept of dual rulership was not new to the Roman Empire.Augustus, the first emperor, had nominally shared power with his colleagues, and a formal office of co-emperor (co-Augustus) had existed fromMarcus Aureliusonward.Most recently, Emperor Carus and his sons had ruled together, albeit unsuccessfully. Diocletian was in a less comfortable position than most of his predecessors, as he had a daughter, Valeria, but no sons. His co-ruler had to be from outside his family, raising the question of trust.Some historians state that Diocletian adopted Maximian as hisfilius Augusti, his "Augustan son", upon his appointment to the throne, following the precedent of some previous Emperors.This argument has not been universally accepted.Diocletian and Maximian added each other'snomina(theirfamily name, "Valerius" and "Aurelius", respectively) to their own, thus creating an artificial family link and becoming part of the "Aurelius Valerius" family. Diocletian and Maximian on an aureus (287 AD) The relationship between Diocletian and Maximian was quickly couched in religious terms. Around 287 Diocletian assumed the titleIovius(Jovius), and Maximian assumed the titleHerculius(Hercules).The titles were probably meant to convey certain characteristics of their associated leaders. Diocletian, inJovianstyle, would take on the dominating roles of planning and commanding; Maximian, inHerculianmode, would act as Jupiter'sheroicsubordinate.For all their religious connotations, the emperors were not "gods" in the tradition of theImperial cult although they may have been hailed as such in Imperialpanegyrics. Instead, they were seen as the gods' representatives, affecting their will on earth.The shift from military acclamation to divine sanctification took the power to appoint emperors away from the army. Religious legitimization elevated Diocletian and Maximian above potential rivals in a way military power and dynastic claims could not. Conflict with Sarmatia and Persia After his acclamation, Maximian was dispatched to fight the rebelBagaudae, insurgent peasants of Gaul. Diocletian returned to the East, progressing slowly.By 2 November, he had only reached Civitas Iovia (Botivo, nearPtuj,Slovenia).In the Balkans during the autumn of 285, he encountered a tribe ofSarmatianswho demanded assistance. The Sarmatians requested that Diocletian either help them recover their lost lands or grant them pasturage rights within the empire. Diocletian refused and fought a battle with them, but was unable to secure a complete victory. The nomadic pressures of theEuropean Plainremained and could not be solved by a single war; soon the Sarmatians would have to be fought again. Diocletian wintered inNicomedia.There may have been a revolt in the eastern provinces at this time, as he brought settlers fromAsiato populate emptied farmlands inThrace.He visitedSyria Palaestinathe following spring,His stay in the East saw diplomatic success in the conflict with Persia: in 287,Bahram IIgranted him precious gifts, declared open friendship with the Empire, and invited Diocletian to visit him.Roman sources insist that the act was entirely voluntary. Around the same time, perhaps in 287,Persia relinquished claims onArmeniaand recognized Roman authority over territory to the west and south of the Tigris. The western portion of Armenia was incorporated into the empire and made a province.Tiridates III, theArsacidclaimant to the Armenian throne and a Roman client, had been disinherited and forced to take refuge in the empire after the Persian conquest of 25253. In 287, he returned to lay claim to the eastern half of his ancestral domain and encountered no opposition.Bahram II's gifts were widely recognized as symbolic of a victory in the ongoingconflict with Persia, and Diocletian was hailed as the "founder of eternal peace". The events might have represented a formal end to Carus's eastern campaign, which probably ended without an acknowledged peace.At the conclusion of discussions with the Persians, Diocletian re-organized the Mesopotamian frontier and fortified the city ofCircesium(Buseire, Syria) on theEuphrates. Maximian made Augustus Maximian's campaigns were not proceeding as smoothly. The Bagaudae had been easily suppressed, butCarausius, the man he had put in charge of operations againstSaxonandFrankishpirateson theSaxon Shore, had, according to literary sources, begun keeping the goods seized from the pirates for himself. Maximian issued a death warrant for his larcenous subordinate. Carausius fled the Continent, proclaimed himself emperor, and agitated Britain and northwestern Gaul into open revolt against Maximian and Diocletian. Far more probable, according to the archaeological evidence, is that Carausius had held some important military post in Britain,already had a firm basis of power in Britain and Northern Gaul, and profited from the lack of legitimacy of the central government.Carausius strove to have his legitimacy as a junior emperor acknowledged by Diocletian: in his coinage, he extolled the "concord" between him and the central power. One bronze piece from 290 read PAX AVGGG, "the Peace of the three Augusti"; on the other side, it showed Carausius together with Diocletian and Maximian, with the caption CARAVSIVS ET FRATRES SVI, "Carausius & his brothers".However, Diocletian could not allow a breakaway regional usurper following inPostumus's footprints to enter, of his own accord, the imperial college. Spurred by the crisis, on 1 April 286,Maximian took up the title ofAugustus(emperor).Unusually, Diocletian could not have been present to witness it. It has even been suggested that Maximian usurped the title and was only later recognized by Diocletian in hopes of avoiding civil war.This suggestion is unpopular, as it is clear that Diocletian meant for Maximian to act with a certain amount of independence.It may be posited that Diocletian felt the need to bind Maximian closer to him, by making him his empowered associate, to avoid the possibility of him striking some sort of deal with Carausius. Carausius, rebel emperor ofRoman Britain. Most of the evidence for Carausius's reign comes from his coinage, which was of generally fine quality. Maximian realized that he could not immediately suppress the rogue commander, so in 287 he campaigned against tribes beyond theRhineinstead.As Carausius was allied to the Franks, Maximian's campaigns could be seen as an effort to deny him a basis of support on the mainland. The following spring, as Maximian prepared a fleet for an expedition against Carausius, Diocletian returned from the East to meet Maximian. The two emperors agreed on a joint campaign against theAlamanni. Diocletian invaded Germania through Raetia while Maximian progressed from Mainz. Each burned crops and food supplies as he went, destroying the Germans' means of sustenance.The two men added territory to the empire and allowed Maximian to continue preparations against Carausius without further disturbance.On his return to the East, Diocletian managed what was probably another rapid campaign against the resurgent Sarmatians. No details survive, but surviving inscriptions indicate that Diocletian took the titleSarmaticus Maximusafter 289. In the East, Diocletian engaged in diplomacy with desert tribes in the regions between Rome and Persia. He might have been attempting to persuade them to ally themselves with Rome, thus reviving the old, Rome-friendly,Palmyrenesphere of influence,or to reduce the frequency of their incursions.No details survive for these events.Some of the princes of these states were Persian client kings, a disturbing fact in light of increasing tensions with the Sassanids.In the West, Maximian lost the fleet built in 288 and 289, probably in the early spring of 290. Thepanegyristwho refers to the loss suggests that its cause was a storm,but this might have been an attempt to conceal an embarrassing military defeat.Diocletian broke off his tour of the Eastern provinces soon thereafter. He returned with haste to the West, reaching Emesa by 10 May 290,and Sirmium on the Danube by 1 July 290. Diocletian met Maximian in Milan either in late December 290 or January 291.The meeting was undertaken with a sense of solemn pageantry. The emperors spent most of their time in public appearances. It has been surmised that the ceremonies were arranged to demonstrate Diocletian's continuing support for his faltering colleague.A deputation from the Roman Senate met with the emperors, renewing its infrequent contact with the Imperial office.The choice of Milan over Rome further snubbed the capital's pride. But then it was already a long-established practice that Rome itself was only a ceremonial capital, as the actual seat of the Imperial administration was determined by the needs of defense. Long before Diocletian,Gallienus(r. 25368) had chosen Milan for his headquarters. If the panegyric detailing the ceremony implied that the true center of the empire was not Rome, but where the emperor sat ("...the capital of the empire appeared to be there, where the two emperors met"),it simply echoed what had already been stated by the historianHerodianin the early third century: "Rome is where the emperor is".During the meeting, decisions on matters of politics and war were probably made in secret.The Augusti would not meet again until 303. Foundation of the Tetrarchy Map of the Roman Empire under the Tetrarchy, showing thediocesesand the four tetrarchs' zones of influence post-299, after Diocletian and Galerius had exchanged their allocated provinces.[image reference needed] Triumphal arch of the Tetrarchy,Sbeitla,Tunisia Some time after his return, and before 293, Diocletian transferred command of the war against Carausius from Maximian toFlavius Constantius, which he concluded successfully in 296. Constantius was a former Governor of Dalmatia and a man of military experience stretching back toAurelian's campaigns againstZenobia(27273). He was Maximian'spraetorian prefectin Gaul, and the husband to Maximian's daughter,Theodora. On 1 March 293 at Milan, Maximian gave Constantius the office of caesar.The same day, in either Philippopolis (Plovdiv,Bulgaria) or Sirmium, Diocletian did the same forGalerius, husband to Diocletian's daughter Valeria, and perhaps Diocletian's praetorian prefect. Constantius was assigned Gaul and Britain. Galerius was initially assigned Syria, Palestine, Egypt, and responsibility for the eastern borderlands. This arrangement is called theTetrarchy, from aGreekterm meaning "rulership by four". The Tetrarchs were more or less sovereign in their own lands, and they travelled with their own imperial courts, administrators, secretaries, and armies.They were joined by blood and marriage; Diocletian and Maximian now styled themselves as brothers, and formally adopted Galerius and Constantius as sons. These relationships implied a line of succession. Galerius and Constantius would becomeAugustiafter the departure of Diocletian and Maximian. Maximian's sonMaxentiusand Constantius's sonConstantinewould then become Caesars. In preparation for their future roles, Constantine and Maxentius were taken to Diocletian's court in Nicomedia. Conflict in the Balkans and Egypt ATrajanictemple on the island ofPhilae, the newly established border between theNobataeandBlemmyesandRoman Egypt. Diocletian spent the spring of 293 travelling with Galerius from Sirmium (Sremska Mitrovica,Serbia) toByzantium(Istanbul,Turkey). Diocletian then returned to Sirmium, where he remained for the following winter and spring. He campaigned successfully against the Sarmatians in 294, probably in the autumn.The Sarmatians' defeat kept them from the Danube provinces for a long time. Meanwhile, Diocletian built forts north of the Danube,part of a new defensive line called theRipa Samartica, atAquincum(Budapest,Hungary), Bononia (Vidin, Bulgaria), Ulcisia Vetera, Castra Florentium, Intercisa (Dunajvros, Hungary), and Onagrinum (Bege, Serbia).In 295 and 296 Diocletian campaigned in the region again, and won a victory over the Carpi in the summer of 296.Later during both 299 and 302, as Diocletian was residing in the East, it was Galerius's turn to campaign victoriously on the Danube. By the end of his reign, Diocletian had secured the entire length of the Danube, provided it with forts, bridgeheads, highways, and walled towns, and sent fifteen or more legions to patrol the region; an inscription atSexaginta Pristaon the Lower Danube extolled restored tranquility to the region. The defense came at a heavy cost but was a significant achievement in an area difficult to defend. Galerius, meanwhile, was engaged during 291293 in disputes inUpper Egypt, where he suppressed a regional uprising.He returned to Syria in 295 to fight the revanchist Persian empire.Diocletian's attempts to bring the Egyptian tax system in line with Imperial standards stirred discontent, and a revolt swept the region after Galerius's departure. The usurperDomitius Domitianusdeclared himselfAugustusin July or August 297. Much of Egypt, includingAlexandria, recognized his rule.Diocletian moved into Egypt to suppress him, first putting down rebels in theThebaidin the autumn of 297, then moving on to besiege Alexandria. Domitianus died in December 297, by which time Diocletian had secured control of the Egyptian countryside. Alexandria, whose defense was organized under Domitianus's formercorrectorAurelius Achilleus, held out probably until March 298. Later in 298, atriumphal columnwas erected in Alexandria to honor Diocletian, known asPompey's Pillar. Bureaucratic affairs were completed during Diocletian's stay: a census took place, and Alexandria, in punishment for its rebellion, lost the ability to mint independently.Diocletian's reforms in the region, combined with those ofSeptimius Severus, brought Egyptian administrative practices much closer to Roman standards.Diocletian travelled south along the Nile the following summer, where he visitedOxyrhynchusandElephantine.In Nubia, he made peace with theNobataeandBlemmyestribes. Under the terms of the peace treaty Rome's borders moved north toPhilaeand the two tribes received an annual gold stipend. Diocletian left Africa quickly after the treaty, moving from Upper Egypt in September 298 to Syria in February 299. He met with Galerius in Mesopotamia. War with Persia RomanIranian relationsandRomanPersian Wars Invasion, counterinvasion Medallion of Diocletian, AD 303. In 294,Narseh, a son of Shapur who had been passed over for the Sassanid succession, came to power in Persia.In early 294, Narseh sent Diocletian the customary package of gifts between the empires, and Diocletian responded with an exchange of ambassadors. Within Persia, Narseh was destroying every trace of his immediate predecessors from public monuments. He sought to identify himself with the warlike kingsArdashir I(r. 22641) andShapur I(r. 24172), who had defeated and imprisoned EmperorValerian(r. 253260) following his failed invasion of theSasanian Empire. Narseh declared war on Rome in 295 or 296. He appears to have first invaded western Armenia, where he seized the lands delivered to Tiridates in the peace of 287.He moved south into Roman Mesopotamia in 297, where he inflicted a severe defeat on Galerius in the region between Carrhae (Harran, Turkey) and Callinicum (Raqqa, Syria). The historianFergus Millarnotes, probably somewhere on theBalikh River).Diocletian may or may not have been present at the battle,but he quickly divested himself of all responsibility. In a public ceremony atAntioch, the official version of events was clear: Galerius was responsible for the defeat; Diocletian was not. Diocletian publicly humiliated Galerius, forcing him to walk for a mile at the head of the Imperial caravan, still clad in the purple robes of the Emperor. Detail ofGaleriusattackingNarsehon theArch of GaleriusatThessaloniki,Greece, the city where Galerius carried out most of his administrative actions. Galerius was reinforced, probably in the spring of 298, by a new contingent collected from the empire's Danubian holdings.Narseh did not advance from Armenia and Mesopotamia, leaving Galerius to lead the offensive in 298 with an attack on northern Mesopotamia via Armenia.It is unclear if Diocletian was present to assist the campaign; he might have returned to Egypt or Syria.Narseh retreated to Armenia to fight Galerius's force, to Narseh's disadvantage; the rugged Armenian terrain was favorable to Roman infantry, but not to Sassanid cavalry. In two battles, Galerius won major victories over Narseh. During thesecond encounter, Roman forces seized Narseh's camp, his treasury, his harem, and his wife.Galerius continued down the Tigris, and took the Persian capital Ctesiphon before returning to Roman territory along the Euphrates. Peace negotiations Narseh sent an ambassador to Galerius to plead for the return of his wives and children in the course of the war, but Galerius dismissed him.Serious peace negotiations began in the spring of 299. Themagister memoriae(secretary) of Diocletian and Galerius, Sicorius Probus, was sent to Narseh to present terms.The conditions of the resultingPeace of Nisibiswere heavy:Armenia returned to Roman domination, with the fort of Ziatha as its border;Caucasian Iberiawould pay allegiance to Rome under a Roman appointee; Nisibis, now under Roman rule, would become the sole conduit for trade between Persia and Rome; and Rome would exercise control over the five satrapies between the Tigris and Armenia:Ingilene, Sophanene (Sophene), Arzanene (Aghdznik),Corduene(Carduene), and Zabdicene (near modernHakkri, Turkey). These regions included the passage of the Tigris through theAnti-Taurusrange; theBitlispass, the quickest southerly route into Persian Armenia; and access to theTur Abdinplateau. A stretch of land containing the later strategic strongholds of Amida (Diyarbakr, Turkey) andBezabdecame under firm Roman military occupation.With these territories, Rome would have an advance station north of Ctesiphon, and would be able to slow any future advance of Persian forces through the region.Many cities east of the Tigris came under Roman control, includingTigranokert,Saird,Martyropolis,Balalesa,Moxos,Daudia, and Arzan though under what status is unclear.At the conclusion of the peace, Tiridates regained both his throne and the entirety of his ancestral claim.Rome secured a wide zone of cultural influence, which led to a wide diffusion ofSyriac Christianityfrom a center at Nisibis in later decades, and the eventual Christianization of Armenia. To strengthen the defence of the east Diocletian had a fortified road constructed at the southern border, where the empire bordered the Arabs, in the year 300. This road would remain in use for centuries but proved ineffective in defending the border as conventional armies could not operate in the region. Religious persecutions Diocletianic Persecution Early persecutions At the conclusion of thePeace of Nisibis, Diocletian and Galerius returned to SyrianAntioch.At some time in 299, the emperors took part in a ceremony ofsacrificeanddivinationin an attempt to predict the future. Theharuspiceswere unable to read the entrails of the sacrificed animals and blamed Christians in the Imperial household. The emperors ordered all members of the court to perform a sacrifice to purify the palace. The emperors sent letters to the military command, demanding the entire army perform the required sacrifices or face discharge.Diocletian was conservative in matters of religion, faithful to the traditional Roman pantheon and understanding of demands for religious purification,butEusebius,LactantiusandConstantinestate that it wasGalerius, not Diocletian, who was the prime supporter of the purge.Galerius, even more devoted and passionate than Diocletian, saw political advantage in the persecution. He was willing to break with a government policy of inaction on the issue. Antioch was Diocletian's primary residence from 299 to 302, while Galerius swapped places with his Augustus on the Middle and Lower Danube. Diocletian visited Egypt once, over the winter of 3012, and issued a grain dole in Alexandria.Following some public disputes withManicheans, Diocletian ordered that the leading followers ofManibe burnt alive along with their scriptures. In a 31 March 302 rescript from Alexandria, he declared that low-status Manicheans must be executed by the blade, and high-status Manicheans must be sent to work in the quarries of Proconnesus (Marmara Island, Turkey) or the mines ofPhaenoin southernPalestine. All Manichean property was to be seized and deposited in theimperial treasury.Diocletian found much to be offended by in Manichean religion: its novelty, its alien origins, its perceived corruption of Roman morals, and its inherent opposition to long-standing religious traditions.His reasons for opposing Manichaeanism were also applied to his next target, Christianity. Great Persecution Catacomb of Saints Marcellinus and Peter on theVia Labicana. Christ betweenPeterandPaul. To the sides are the martyrs Gorgonius, Peter, Marcellinus,Tiburtius Diocletian returned to Antioch in the autumn of 302. He ordered that thedeaconRomanus of Caesareahave his tongue removed for defying the order of the courts and interrupting official sacrifices. Romanus was then sent to prison, where he was executed on 17 November 303. Diocletian left the city for Nicomedia in the winter, accompanied by Galerius.[175]According to Lactantius, Diocletian and Galerius argued over imperial policy towards Christians while wintering at Nicomedia in 302. Diocletian believed that forbidding Christians from the bureaucracy and military would be sufficient to appease the gods, but Galerius pushed for extermination. The two men sought the advice of theoracleofApolloatDidyma.The oracle responded that the impious on Earth hindered Apollo's ability to provide advice. Rhetorically Eusebius records the Oracle as saying "The just on Earth..."These impious, Diocletian was informed by members of the court, could only refer to the Christians of the empire. At the behest of his court, Diocletian acceded to demands for universal persecution. On 23 February 303, Diocletian ordered that the newly built church at Nicomedia be razed. He demanded that its scriptures be burned, and seized its precious stores for the treasury.The next day, Diocletian's first "Edict against the Christians" was published.The edict ordered the destruction of Christian scriptures and places of worship across the empire, and prohibited Christians from assembling for worship.Before the end of February, a fire destroyed part of the Imperial palace.Galerius convinced Diocletian that the culprits were Christians, conspirators who had plotted with theeunuchsof the palace. An investigation was commissioned, but no responsible party was found. Executions followed anyway, and the palace eunuchs Dorotheus andGorgoniuswere executed. One individual,Peter Cubicularius, was stripped, raised high, and scourged. Salt and vinegar were poured in his wounds, and he wasslowly boiledover an open flame. The executions continued until at least 24 April 303, when six individuals, including thebishopAnthimus, weredecapitated.A second fire occurred sixteen days after the first. Galerius left the city for Rome, declaring Nicomedia unsafe.Diocletian would soon follow. Although further persecutory edicts followed, compelling the arrest of the Christian clergy and universal acts of sacrifice,they were ultimately unsuccessful; most Christians escaped punishment, and pagans too were generally unsympathetic to the persecution. Themartyrs' sufferings strengthened the resolve of their fellow Christians.Constantius and Maximian did not apply the later edicts, and left the Christians of the West unharmed.Galerius rescinded the edict in 311, announcing that the persecution had failed to bring Christians back to traditional religion.The temporary apostasy of some Christians, and the surrendering of scriptures, during the persecution played a major role in the subsequentDonatistcontroversy.Within twenty-five years of the persecution's inauguration, the Christian emperorConstantinewould rule the empire alone. He would reverse the consequences of the edicts, and return all confiscated property to Christians.Under Constantine's rule, Christianity would become the empire's preferred religion.Diocletian was demonized by his Christian successors:Lactantiusintimated that Diocletian's ascendancy heralded the apocalypse. Later life Illness and abdication Reconstruction of thePalace of the Roman Emperor Diocletianin its original appearance upon completion in 305, byErnest Hbrard Modern-day Diocletian's Palace (2012), as the core of the city ofSplit Diocletian entered the city of Rome in the early winter of 303. On 20 November, he celebrated, with Maximian, the twentieth anniversary of his reign (vicennalia), the tenth anniversary of the Tetrarchy (decennalia), and a triumph for the war with Persia. Diocletian soon grew impatient with the city, as the Romans acted towards him with whatEdward Gibbon, followingLactantius, calls "licentious familiarity".The Roman people did not give enough deference to his supreme authority; it expected him to act the part of an aristocratic ruler, not a monarchic one. On 20 December 303,Diocletian cut short his stay in Rome and left for the north. He did not even perform the ceremonies investing him with his ninth consulate; he did them inRavennaon 1 January 304 instead.There are suggestions in thePanegyrici Latiniand Lactantius's account that Diocletian arranged plans for his and Maximian's future retirement of power in Rome. Maximian, according to these accounts, swore to uphold Diocletian's plan in a ceremony in theTemple of Jupiter. From Ravenna, Diocletian left for the Danube. There, possibly in Galerius's company, he took part in a campaign against the Carpi.He contracted a minor illness while on campaign, but his condition quickly worsened and he chose to travel in alitter. In the late summer, he left for Nicomedia. On 20 November 304, he appeared in public to dedicate the opening of the circus beside his palace. He collapsed soon after the ceremonies. Over the winter of 3045 he kept within his palace at all times. Rumours that Diocletian's death was being kept secret until Galerius could assume power spread through the city. On 13 December, it was falsely announced that Diocletian had killed himself. The city was sent into mourning from which it recovered after public declarations that Diocletian was still alive. When Diocletian reappeared in public on 1 March 305, he was emaciated and barely recognizable. Galerius arrived in the city later in March. According toLactantius, he came armed with plans to reconstitute the Tetrarchy, force Diocletian to step down, and fill the Imperial office with men compliant to his will. Through coercion and threats, he eventually convinced Diocletian to comply with his plan. Lactantius also claims that he had done the same to Maximian at Sirmium.On 1 May 305, Diocletian called an assembly of his generals, traditional companion troops, and representatives from distant legions. They met at the same hill, 5 kilometres (3.1mi) out of Nicomedia, where Diocletian had been proclaimed emperor. In front of a statue of Jupiter, his patron deity, Diocletian addressed the crowd. With tears in his eyes, he told them of his weakness, his need for rest, and his will to resign. He declared that he needed to pass the duty of empire on to someone stronger. He thus became the first Roman emperor to voluntarily abdicate his title. Most in the crowd believed thatConstantineand Maxentius, the only adult sons of reigning emperors, who had long been preparing to succeed their fathers, would be granted the title ofCaesar. Constantine had travelled through Palestine at the right hand of Diocletian, and was present at the palace in Nicomedia in 303 and 305. It is likely that Maxentius received the same treatment.In Lactantius's account, when Diocletian announced that he was to resign, the entire crowd turned to face Constantine.It was not to be:Severus IIandMaximinus IIwere declared caesars. Maximinus appeared and took Diocletian's robes. On the same day, Severus received his robes from Maximian in Milan. Constantius succeeded Maximian asAugustusof the West, but Constantine and Maxentius were entirely ignored in the transition of power. This did not bode well for the future security of the tetrarchic system. Retirement and death Modern view of thePeristyleinDiocletian's Palace(Split,Croatia) Diocletian retired to his homeland,Dalmatia. He moved into the expansiveDiocletian's Palace, a heavily fortified compound located by the small town of Spalatum on the shores of theAdriatic Sea, and near the large provincial administrative center ofSalona. The palace is preserved in great part to this day and forms the historic core ofSplit, the second-largest city of modernCroatia. Maximian retired to villas inCampaniaorLucania. Their homes were distant from political life, but Diocletian and Maximian were close enough to remain in regular contact with each other.Galerius assumed the consularfascesin 308 with Diocletian as his colleague. In the autumn of 308, Galerius again conferred with Diocletian atCarnuntum(Petronell-Carnuntum,Austria). Diocletian and Maximian were both present on 11 November 308, to see Galerius appointLiciniusto be Augustus in place of Severus, who had died at the hands of Maxentius. He ordered Maximian, who had attempted to return to power after his retirement, to step down permanently. At Carnuntum people begged Diocletian to return to the throne, to resolve the conflicts that had arisen through Constantine's rise to power and Maxentius's usurpation.Diocletian's reply: "If you could show thecabbagethat I planted with my own hands to your emperor, he definitely wouldn't dare suggest that I replace the peace and happiness of this place with the storms of a never-satisfied greed." Diocletian lived for four more years, spending his days in his palace gardens. He saw his tetrarchic system fail, torn apart by thecivil wars of his successors. He heard of Maximian's third claim to the throne, his forced suicide, and hisdamnatio memoriae. In his own palace, statues and portraits of his former companion emperor were torn down and destroyed. After an illness, Diocletian died on 3 December 311, with some proposing that hetook his own lifein despair. Currency and inflation A fragment of theEdict on Maximum Prices(301), on display inBerlin