The oldest remains found in Syria date from the Palaeolithic era (c.800,000 BCE). Archaeologists have demonstrated that civilization in Syria was one of the most ancient on earth.
The Umayyad Mosque was built on the site of the Roman Temple of Jupiter, converted into the Church of St John the Baptist in 379 CE. After the Islamic conquest of Damascus, the holy site was shared between the Christians and the Muslims of the city. By the succession of the Umayyad Caliph al-Walid bin Abd al-Malik, the church was demolished and a vast congregational mosque constructed instead.