located in Iran) was captured by Rome five times in its history - three times in the 2nd century alone. The emperor Trajan captured Ctesiphon in 116 AD, but his successor, Hadrian, decided to willingly return Ctesiphon the next year as part of a peace settlement. The Roman general Avidius Cassius captured Ctesiphon in 164 AD during another Parthian war, but abandoned it when peace was concluded. In 197 AD, the emperor Septimius Severus sacked Ctesiphon and carried off thousands of its inhabitants, whom he sold into slavery. Late in the 3rd century, after the Parthians had been supplanted by the Sassanids, the city again became a source of conflict with Rome. In 283 AD, emperor Carus sacked the city uncontested during a period of civil upheaval. In 295 AD, emperor Diocletianus sent Galerius but was defeated outside the city. However, he returned a year later with a vengeance and won a victory which ended in the fifth and final capture of the city by the Romans in 299 AD. Furthermore, in 297 AD Galerius marched into eastern Armenia and crushed there a Persian force, capturing an enormous amount of booty and even the harem and family of the Sassanian King Narseh. Moving later into Mesopotamia, Galerius' advance had the Persian defence collapsing before him and so he conquered the Persian capital Ctesiphon. Badly mauled, the Persians sued for peace. In AD 298 the province of Mesopotamia, together with even some territory from across the river Tigris up to the lacus Matianus (now called Lake Urmia in western Iran), was restored to Rome for half a century with an important Treaty. According to this Treaty: Five provinces beyond the Tigris were to be ceded to the Romans. One writer gives these provinces as Intilene, Sophene, Arzanene, Carduene, and Zabdicene; while another as Arzanene, Moxoene, Zabdicene, Rehimene, and Corduene. The Roman vassal "Kingdom of Armenia" was to be extended up to the fortress of Zintha, in Media Atropatene. Galerius (who occupied western Persia up to lake Matianus) wanted to conquest all Persia after his victory against Sassanian king Narseh, but Diocletianus preferred to have a Treaty and did the last "Parade" in Rome with a significant victory in the history of the Roman Empire. Romans withdrew from the homeland territory of Persia with the 363 AD defeat of Jovian, and only Byzantine emperor Heraclius was able to return and conquer Gazaca