In 727, the Arab army, led by one of the Caliph's sons, penetrated deep into Asia Minor, sacked two Byzantine fortresses and in late July arrived before Nicaea.

The Muslim raids across the Taurus Mountains into Byzantine Asia Minor still occurred regularly every spring and summer, sometimes accompanied by naval raids and followed by a winter expedition; they devastated large tracts of Asia Minor, and destroyed several fortresses; but the Arabs did not attempt to hold on to captured strongholds on the west side of the Taurus Mountains.

The Arabs assaulted the city for forty days, employing siege engines which destroyed a part of the walls, but eventually failed to take it.

[9][10][15][16] The 12th-century chronicle of Michael the Syrian claims that the city's inhabitants abandoned it and fled by ship through Lake Ascania, whereupon the Arabs destroyed Nicaea, but this is clearly an error.

Emperor Leo III the Isaurian (r. 717–741) regarded the city's survival as a sign of divine favour towards his newly instituted iconoclastic policies, and was encouraged to drive them further.

[18] This is probably related to an incident mentioned in the account of Theophanes, where a certain Constantine, who served as a groom (strator) to Artabasdos, threw a stone on an icon of the Virgin Mary and then trampled on it.

By 740, when the Umayyads assembled the largest invasion force fielded after 718, the Byzantines had recovered enough to inflict a heavy defeat against them at the Battle of Akroinon.