After the Muslim conquest of Damascus in 634 CE, the mosque was built on the site of a Christian basilica dedicated to John the Baptist, honored as a prophet by Christians and Muslims. A legend dating to the sixth century holds that the building contains the head of John the Baptist.

The site is attested for as a place of worship since the Iron Age. Damascus was the capital of the Aramaean state Aram-Damascus and a large temple dedicated to the cult of Hadad-Ramman, the god of thunderstorms and rain, was erected at the site of the present-day Umayyad Mosque. One stone remains from the Aramaean temple, dated to the rule of King Hazael, and is currently on display in the National Museum of Damascus.

circa 700 CE

The sixth Umayyad caliph, al-Walid I (r. 705–715), commissioned the construction of a mosque on the site of the Byzantine cathedral in 706 CE. Prior to this, the cathedral was still in use by the local Christians, but a prayer room (musalla) for Muslims had been constructed on the southeastern part of the building. al-Walid, who personally supervised the project, had most of the cathedral, including the musalla, demolished. The construction of the mosque completely altered the layout of the existing building. According to 10th-century CE Persian historian Ibn al-Faqih, somewhere between 600,000 and 1,000,000 dinars were spent on the project. Coptic craftsmen as well as Persian, Indian, Greek and Moroccan laborers provided the bulk of the labor force which consisted of 12,000 people.

circa 700 CE

Interior
The Umayyad Mosque is one of the few early mosques in the world to have maintained the same general structure and architectural features since its initial construction in the early 8th century and its Umayyad character has not been significantly altered. In the center of the sanctuary with a larger, higher arcade that is perpendicular to the qibla ("direction of prayer") wall and faces the mihrab (niche in the wall which indicates the qibla) and the minbar ("pulpit").

circa 700 CE

Mosaics
Byzantine artisans were employed to create the mosaics, still visible, which depict landscapes and buildings in a characteristic late Roman style. Muhammad al-Idrisi relates, In Damascus there is a mosque that has no equal in the world, not one with such fine proportion, nor one so solidly constructed, nor one vaulted so securely, nor one more marvellously laid out, nor one so admirably decorated in gold mosaics and diverse designs, with enamelled tiles and polished marbles.

circa 700 CE

Minarets
Minaret of Jesus is the tallest of all minarets of Umayyad Mosque in Damascus. It was was destroyed at the hands of as-Salih Ayyub while besieging as-Salih Ismail in 1245 and was later rebuilt with little decoration. The mosque is also believed by Muslims to be the place where Jesus (Isa) will return at the End of Days. The main body of the current minaret was built by the Ayyubids in 1247, but the upper section was constructed by the Ottomans.

circa 790 CE

Domes
Treasury Dome is one of the domes of Umayyad Mosque where the treasury funds and some Greek and other historic manuscripts used to be stored until late 17th century. The Abbasid governor of Damascus, al-Fadl ibn Salih ibn Ali, nine years later, initiated the construction of the Dome of the Treasury with the purpose of housing the mosque's funds.

circa 1300 CE

Sundial of Ibn Shatir
Replica of the Ibn Shatir's sundial, developed by ibn Shatir, atop the Madhanat al-Arus (The Minaret of the Bride) in Umayyad Mosque. Original sundial was removed in the eighteenth century, short time afterwards, an exact replica was installed atop the first built Madhanat al-Arus (The Minaret of the Bride) in Umayyad Mosque.

circa 790 CE

Shrine of Yahya's Head
Shrine of John the Baptist (Maqam-i Ra's-i Nabi Yahya). According to Islamic and Christian tradition, (legend had it that) Saint John's head was buried there. Ibn al-Faqih relays the story that during the construction of the mosque, workers found a cave-chapel which had a box containing the head of St. John the Baptist, or Yaḥyā ibn Zakarīyā in Islam. Upon learning of that and examining it, al-Walid I ordered the head buried under a specific pillar in the mosque that was later inlaid with marble.

circa 790 CE

Gates
There are four gates of the Jami Umavi al-Kabir, each in one of the four walls.

circa 790 CE

The mosque's extensive mosaics and its marble panelling were once again ravaged by fire in 1893, and had to be restored. The fire also destroyed the inner fabric of the prayer hall and caused the collapse of the mosque's central dome.

circa 790 CE

The mausoleum of Saladin stands in a small garden adjoining the north wall of the mosque. The Mausoleum of Saladin holds the grave of the medieval Ayyubid sultan, Saladin (Ṣalāḥ ad-Dīn Yūsuf ibn Ayyūb, circa 1138-March 4, 1193). The mausoleum was built in 1196, three years after the death of Saladin by his son, al-Adil I. It was once part of the al-Aziziyah madrasa, but nothing remains of the school.