The Church of SS Cosmas and Damian, which has a basilica plan, is the northernmost church in a complex of three adjoined Byzantine churches from the early 6th century CE (the other two being the Church of St John the Baptist and the Church of St George). The church was dedicated on 533 CE, according to an inscription in the nave's exquisitely preserved mosaic floor.
Sources:
Khouri, Rami G. Jerash: A Brief Guide to the Antiquities. Amman: Al Kutba, 1988.
Rautmann, M., and J. M. C. Bowsher. "Gerasa." Grove Art Online. 2003; Accessed 17 Oct. 2019. https://www.oxfordartonline.com/groveart/view/10.1093/gao/9781884446054.001.0001/oao-9781884446054-e-7000031479.