The Umayyad Mosque, also known as the Great Mosque of Damascus (Arabic: جامع بني أمية الكبير, transliteration Ğām’ Banī ‘Umayya al-Kabīr) or formerly the Basilica of Saint John the Baptist (Greek: Βασιλική του Αγίου Ιωάννη του Βαπτιστή, transliteration Vasilikí tou Agíou Ioánni tou Vaptistí), is located in the old city of Damascus, is one of the largest and oldest mosques in the world.
After the Arab conquest of Damascus in 634, the mosque was built on the site of a Christian basilica dedicated to John the Baptist (Yahya) since the time of the Roman emperor Constantine I. The mosque holds a shrine which today may still contain the head of John the Baptist, honored as a prophet by both Christians and Muslims alike. There are also many important landmarks within the mosque for the Shī‘ah, among them the place where the head of Husayn (the grandson of Muhammad) was kept on display by Yazīd I. The tomb of Saladin stands in a small garden adjoining the north wall of the mosque.
[Umayyad Mosque – Wikipedia, the free encyclopedia.mht]