David's Citadel was an ancient citadel located in the middle district of Jerusalem. The citadel was used by Romans as barracks in 70 AD. After the Arab conquest of Jerusalem, the new Muslim rulers refurbished the ancient building. It even withstood the assault of the Crusaders in 1099, but was later used as the seat of the Crusader kings of Jerusalem.
In 1191, the Templar Majd Addin was buried on a small graveyard in front of the citadel. The funeral was infiltrated by the Assassin Altaïr Ibn-La'Ahad with the intention of killing Robert de Sable, the Grand Master of the Templar Order; Altaïr ended up being discovered, however, and fled the funeral following his confrontation with Maria Thorpe, who had impersonated Robert as a distraction.
- Despite being one of the biggest and highest buildings in Assassin's Creed, it is not climbable and only minor parts of it can be entered.
- The citadel was rebuilt by Suleiman the Magnificent during the 16th century.
- The citadel was most likely named after King David of Jerusalem.
- In the Assassins' Bureau, Malik al-Sayf kept a map of Jerusalem, on which only minor parts of David's Citadel were marked.