The city that fell to the Crusaders after a seven-month siege in 1153 was Ascalon.
Ascalon was a heavily fortified Fatimid coastal city and a major base for raids against the Kingdom of Jerusalem. By 1153, it was the last important coastal city in Palestine still controlled by the Fatimid Caliphate. King Baldwin III of Jerusalem began the siege on 25 January, attacking by land while a small Crusader fleet operated offshore.
The siege stalled for months until a Fatimid attempt to burn a Crusader siege tower backfired. Wind pushed the flames against Ascalon's own walls, causing a breach. Knights Templar entered first but were overwhelmed, and about forty Templars, including Grand Master Bernard de Tremelay, were killed. A larger assault followed soon afterward.
The city fell on 19 August and formally surrendered on 22 August 1153. Its inhabitants were allowed three days to leave, and many departed for Egypt. Ascalon's capture strengthened Jerusalem's southern frontier and gave the Crusaders a potential base for future campaigns against Egypt.