This is the oldest known Byzantine church in Jerash and was probably built around 450/455 AD when the bishop of Gerasa was Bishop Placcus. The site was previously occupied by a pagan sanctuary, perhaps dedicated to Dionysos, the god of wine. During his reign Bishop Placcus dismantled the Temple of Zeus and used some of the stones for this church, as well as to build the nearby baths named after him. This church was dubbed "the Cathedral" by the American excavation team that unearthed it in 1929.

The wonderful architecture of the Cathedral is still apparent in what remains today. The main entrance is on the west side from the Fountain Courtyard. Eight other entrances also allowed access to the church, and inside the space is partitioned into three sections by two rows of columns with an apse at the front of the church that only the priest would have access to. Note the holes in the columns and walls, which may have been for attaching decorative plaster panels and bronze embellishments.
(From information on site)

In the background, the Fountain Court and the Church of St. Theodore.