Alternative forms and spellings include: Kal'at instead of Qal'at, the prefix as- instead of al-, and Subayba, Subaybah and Subeibeh in place of Subeiba.

The association of the fortress with the biblical king, mighty warrior and hunter Nimrod, who entered post-koranic Islamic interpretive literature as Nimrud, came from the Druze, who only settled in the area in the 19th century.

[3] The fortress was rebuilt[3] around 1228 by Al-Aziz Uthman, the son of Saladin's brother al-'Adil, to preempt an attack on Damascus by the armies of the Sixth Crusade.

In 1260 the Mongols captured the castle, dismantled some of its defenses and left their ally, the son of Al-Aziz 'Uthman, in charge of it and the nearby town of Banias.

[6] After the subsequent Mamluk victory over the Mongols at the Battle of Ain Jalut, Sultan Baibars strengthened the castle and added larger towers.

Overlooking the high, eastern edge of the fortress stood a large keep, measuring 65 by 45 metres (200 by 150 feet) and protected by massive rectangular towers.

[9] The fortress overlooks the deep, narrow valley that separates Mount Hermon from the rest of the Golan Heights, the road linking the Galilee with Damascus, and the former Crusader town of Banias.

They were designed specifically for shooting bows and arrows or crossbows, giving the defender inside the fortress plenty of room but the attacker only a narrow slit as a target.