The By No Means Mild Quake struck Syria and neighboring Upper Mesopotamia in March 756 CE. Contemperaneous Pseudo-Dionysius of Tell-Mahre describes a "powerful, terrible and dreadful earthquake" during the night of 3 March in Jazira (Upper Mesopotamia). He reports that three villages along the Khabur River collapsed, killing many of their inhabitants, and adds that "many other places were also destroyed."

Theophanes records a "considerable earthquake in Palestine and Syria" on 9 March 756 CE. His reference to Syria is geographically compatible with Pseudo-Dionysius' account of destruction along the Khabur. Theophanes' extension of the affected area into Palestine may reflect a separate earthquake. One possibility is the second al-Aqsa earthquake, which Williams (2024) places after the first repair of al-Aqsa under al-Mansur (r. 754–775 CE) and before 785 CE, and which was presumably centered in or near Jerusalem.