Krak des Chevaliers (French pronunciation: [kʁak de ʃəvaˈlje]) (Arabic: قلعة الحصن), also Crac des Chevaliers, is a Crusader castle in Syria and one of the most important preserved medieval castles in the world. The site was first inhabited in the 11th century by a settlement of Kurds; as a result it was known as Hisn al Akrad, meaning the "Castle of the Kurds". In 1142 it was given by Raymond II, Count of Tripoli, to the Knights Hospitaller. It remained in their possession until it fell in 1271. It became known as Crac de l'Ospital; the name Krak des Chevaliers was coined in the 19th century.
The Hospitallers began rebuilding the castle in the 1140s and were finished by 1170 when an earthquake damaged the castle. The order controlled a number of castles along the border of the County of Tripoli, a state founded after the First Crusade. Krak des Chevaliers was amongst the most important and acted as a centre of administration as well as a military base. After a second phase of building was undertaken in the 13th century, Krak des Chevaliers became a concentric castle. This phase created the outer wall and gave the castle its current appearance. The first half of the century has been described as Krak des Chevaliers' "golden age". At its peak, Krak des Chevaliers housed a garrison of around 2,000. Such a large garrison allowed the Hospitallers to extract tribute from a wide area. From the 1250s the fortunes of the Knights Hospitaller took a turn for the worse and in 1271 Krak des Chevaliers was captured by the Mamluk Sultan Baibars after a siege lasting 36 days, and then purportedly only by way of a forged letter purportedly from the Hospitallers' Grand Master that caused the Knights to surrender.
A castle (from Latin: castellum) is a type of fortified structure built in Europe and the Middle East during the Middle Ages by nobility. Scholars debate the scope of the word castle, but usually consider it to be the private fortified residence of a lord or noble. This is distinct from a palace, which is not fortified; from a fortress, which was not always a residence for nobility; and from a fortified settlement, which was a public defence – though there are many similarities among these types of construction. Usage of the term has varied over time and has been applied to structures as diverse as hill forts and country houses. Over the approximately 900 years that castles were built they took on a great many forms with many different features, although some, such as curtain walls and arrowslits, were commonplace.
A European innovation, castles originated in the 9th and 10th centuries, after the fall of the Carolingian Empire resulted in its territory being divided among individual lords and princes. These nobles built castles to control the area immediately surrounding them, and were both offensive and defensive structures; they provided a base from which raids could be launched as well as protection from enemies. Although their military origins are often emphasised in castle studies, the structures also served as centres of administration and symbols of power. Urban castles were used to control the local populace and important travel routes, and rural castles were often situated near features that were integral to life in the community, such as mills and fertile land.