Jerash is home to a large Roman city complex (roads, temples). Originally Alexander the Great had the city built but when the Romans invaded they changed everything to the Roman design.
The Romans remained there until the fourth century when they converted to Christianity and the Byzantine Age took over. This lasted until the Islamic Age in 638 CE. Umayyad settled in Jarash (Jerash) in 661 and turned some of the Roman buildings into houses for soldiers. After the Crusades the Ottomans ruled (1516) and brought people to inhabit Jerash.