Krak des Chevaliers (pronounced [kʁak de ʃəval'je]), transliterated Crac des Chevaliers, is a Crusader fortress in Syria and one of the most important preserved medieval military castles in the world. In Arabic, the fortress is called Qal'at al-Ḥiṣn (Arabic: قلعة الحصن), the word Krak coming from the Syriac karak, meaning fortress.
The castle is located east of Tripoli, Lebanon, in the Hims Gap, atop a 650-metre-high hill along the only route from Antioch to Beirut and the Mediterranean Sea. It is one of many fortresses that were part of a defensive network along the border of the old Crusader states. The fortress controlled the road to the Mediterranean, and from this base, the Hospitallers could exert some influence over Lake Homs to the east to control the fishing industry and watch for Muslim armies gathering in Syria.
During the First Crusade in 1099 it was captured by Raymond IV of Toulouse, but then abandoned when the Crusaders continued their march towards Jerusalem. It was reoccupied again by Tancred, Prince of Galilee in 1110. In 1142 it was given by Raymond II, count of Tripoli, to the Hospitallers, contemporaries of the Knights Templar.
Krak des Chevaliers was the headquarters of the Knights Hospitaller during the Crusades. It was expanded between 1150 and 1250 and eventually housed a garrison of 2,000. The inner curtain wall is up to 100 feet thick at the base on the south side, with seven guard towers 30 feet in diameter.
The Hospitallers rebuilt it and expanded it into the largest Crusader fortress in the Holy Land, adding an outer wall three meters thick with seven guard towers eight to ten meters thick to create a concentric castle.
The fortress may have held about 50-60 Hospitallers and up to 2,000 other foot soldiers; the Grand Master of the Hospitallers lived in one of the towers. In the 12th century the fortress had a moat which was covered by a drawbridge leading to postern gates.