The Temple of Jupiter in Damascus was built by the Romans, beginning during the rule of Augustus and completed during the rule of Constantius II.An ancient Aramaean temple to Hadad once stood on this site. The Romans associated Hadad with Jupiter, and rebuilt the temple in Jupiter's name. The temple drew large crowds to its festivals and Damascus became famous as the city of Jupiter.
Theodosius I converted the temple to a church dedicated to John the Baptist. After the Muslims took over Damascus in 635, the church was shared for seventy years, but Al-Walid I converted it to the Umayyad Mosque.
The inner court, or temenos is believed to have been completed soon after the end of Augustus' reign in 14 AD. This was surrounded by an outer court, or peribolos which included a market, and was built in stages as funds permitted, and completed in the middle of the first century CE. At this time the eastern gateway or propylaeum was built. The end of the second, century during the reign of Septimius Severus, saw a major upgrading in a more flamboyant style.