Editing Urfa (section)

====Late antiquity====
In the 4th through 6th centuries AD, Edessa went through arguably its period of greatest prosperity. It was again an important commercial center, and merchants grew rich on trade in luxury goods from the east, particularly silk. As with later periods, the city had a council of notable citizens who were at least partly in charge of local government and administration. In the 5th century there were three different theological schools in Edessa: the School of the Syrians (affiliated with the patriarchate of Antioch), the School of the Armenians, and the famous School of the Persians (whose teachers were not actually Persians but rather members of the [[Church of the East]]). The School of the Persians was closed down in 489 and its staff relocated to Nisibis. There were many churches in the city and monasteries in the area. Just outside the walls were several infirmaries and hospitals.<ref name="Sinclair 1990"/>{{rp|198}}

When the Roman emperor [[Jovian (emperor)|Jovian]] surrendered Nisibis to the Sasanians in 363, an influx of refugees came to Edessa, including many Christians.<ref name="Lieu 1997"/> One of these refugees was the writer and theologian [[Ephrem the Syrian]], who was a co-founder of the School of the Persians in Edessa.<ref name="Lieu 1997"/> According to T.A. Sinclair, as Christianity gained more of a presence in Edessa, the pagan planet-worshippers increasingly emigrated to Harran.<ref name="Sinclair 1990"/>{{rp|198}}

By the early 6th century, a small lake had formed on the west side of the city. In 525, a flood destroyed part of the western city wall and damaged some of the city. Afterwards, a deep ditch was dug on the north and east sides of the city to act as a [[flood channel]]. In normal weather, a low dam kept the Daisan river in its original course, but if the dam overflowed, then the floodwaters would flow through the artificial channel instead of into the city. At some point later on, the flood channel became the normal course of the river.<ref name="Sinclair 1990"/>{{rp|3}}

Edessa successfully held out during a siege in 544.<ref name="Lieu 1997"/> In 609, however, the Sasanian emperor [[Khosrow II]] captured Edessa during his campaign in Mesopotamia.<ref name="Lieu 1997"/> Many of the city's Monophysites were deported to Iran.<ref name="Lieu 1997"/> In 628, the Byzantine emperor [[Heraclius]] captured Edessa.<ref name="Lieu 1997"/>