Ajlun Castle is located on the site of an old monastery. It was renovated as a fort in 1184 by Izz al-Din Usama, a general in the army of Saladin. The castle controlled traffic along the road connecting Damascus and Egypt. The fortress marks the furthest limit of Frankish incursions during the Crusades. The Mamluks added a prominent tower to the castle. It was captured by the Mongols in 1260 and was partially destroyed in the process. Great damage was done by the Galilee earthquake of 1837 and the 1927 Jericho earthquake.