1138 Aleppo Earthquake

In October 1138, a massive earthquake devastated the city of Aleppo in what is now northern Syria, killing an estimated 230,000 people and reducing the city's fortifications and surrounding settlements to rubble. The quake struck during the Crusader period and was part of a destructive seismic sequence that also included a major 1202 earthquake in the same region. Medieval chroniclers described mountains collapsing and entire villages disappearing; modern seismologists believe it may have reached a magnitude of 7.1 or higher. It ranks as the fourth deadliest earthquake of all time.