Resafa (Arabic: الرصافة, romanized: Reṣafa), sometimes spelled Rusafa, and known in the Byzantine era as Sergiopolis (Greek: Σεργιούπολις or Σεργιόπολις, lit.

Resafa corresponds to the Akkadian Raṣappa and the Biblical Rezeph (Septuagint; Koinē Greek: Ράφες), where it is mentioned in Isaiah 37:12;[3][4] cuneiform sources give Rasaappa, Rasappa, and Rasapi.

[10] By the late 6th century, the Ghassanids' tribal Arab ally the Bahra' were tasked with guarding Resafa and its shrine from nomadic marauders and the Lakhmids of Mesopotamia.

In the eighth century, the Umayyad caliph Hisham ibn Abd al-Malik (r. 724–743) made the city his favoured residence, and built several palaces around it,[12] which are counted among the qasr or desert castle category.

[14] Sergiopolis's first bishop was appointed shortly after 431 by John of Antioch, in spite of the opposition of the Metropolitan of Hierapolis Bambyce, on whom that church had till then depended.

Bishop Candidus, at the time of the Sassanian Persian siege of the city by Khosrau I (in 543), ransomed 1,200 captives for two hundred pounds of gold,[15] and, in 1093, Metropolitan Simeon restored the great Basilica ("Échos d'Orient", III, 238); which attests to the continuing existence of Christianity in Rasafa.