Ajloun Castle, also known as Qal’at ar-Rabad, was founded in 1184 by Izz al-Din Usama, a commander and relative of Saladin. The hilltop position controlled routes through northwestern Jordan and provided views toward the Jordan Valley. Its purpose was to counter Crusader power, protect communication between Damascus and southern territories, defend local communities, and supervise valuable resources including iron mines and agricultural land. The fortress formed part of the broader Ayyubid strategy that preceded the defeat of the Crusader army at Hattin in 1187.

The first castle had four corner towers joined by thick curtain walls, a defended entrance, arrow slits, vaulted rooms, cisterns, and a surrounding rock-cut moat. Builders used local limestone and adapted the plan to the ridge. Its compact geometry allowed defenders to observe approaches and move between levels under cover. Water storage was essential during siege, while nearby villages supplied food, animals, labor, and information. The castle’s strength came as much from its position within a regional network as from its masonry.

Expansion around 1214–15 added a southeastern tower and strengthened the gate complex. After Ayyubid control removed the immediate Crusader threat east of the Jordan, the fortress took on administrative, storage, and communication roles. Mongol forces damaged it in 1260. Following the Mamluk victory at Ayn Jalut, Sultan Baybars ordered restoration, and the castle supported Mamluk government and postal routes. Inscriptions and successive masonry phases record officials who repaired and occupied the site rather than leaving it fixed in its original Ayyubid form.

Ajloun remained in use during the Ottoman period, at times housing soldiers, officials, local rulers, and stores. Travelers described an inhabited but weathered fortress. Major earthquakes in 1837 and 1927 caused collapses that added to centuries of alteration, stone reuse, and neglect. The ruin nevertheless retained substantial towers, chambers, stairs, passages, and reservoirs. Its visibility made it a powerful regional landmark and encouraged archaeological clearing, architectural study, and state-sponsored consolidation during the twentieth century.

The Jordanian Department of Antiquities has restored walls, bridges, roofs, and visitor routes while preserving evidence of damage and rebuilding. Museum displays present ceramics, inscriptions, weapons, and objects from the castle and surrounding area. Ajloun’s history complicates the idea of a fortress built only for one crusading confrontation. It served Ayyubid defense, Mamluk administration, Ottoman occupation, local refuge, and modern heritage. From its hill, the landscape still explains the original strategic logic: command of roads, fertile uplands, water, and long views across northern Jordan.