Siege of Shaizar
1157 CE.
Shown on the map at 35.268°, 36.567°.
The siege of Shaizar in late 1157 was part of the effort of the leaders of the crusader states to take advantage of the illness of the Syrian ruler Nur ad-Din Zengi and expand eastwards. King Baldwin III of Jerusalem, Prince Raynald of Antioch, and Counts Thierry of Flanders and Raymond III of Tripoli successfully seized the lower city, but a dispute over the future status of Shaizar erupted between them while they were attacking the citadel, and they withdrew because they could not settle it.
Text from the Wikipedia article Siege of Shaizar (1157), licensed CC BY-SA 4.0.