Tortosa (mod. Tartūs, Syria) was a small port town at the northern end of the county of Tripoli.
The town was acquired by the Order of the Temple, probably in the 1150s. It was surrounded by walls (which have now largely disappeared) and contained a twelfth-century cathedral, now a museum. This is one of the most perfect surviving examples of Frankish ecclesiastical architecture in a simple early gothic style with a pointed barrel-vaulted roof. At the northwest corner of the city, the Templars built a castle. The twelfth-century donjon was strengthened (probably between 1202 and 1212) by the addition of shooting galleries and a bailey surrounded by ditches and a double curtain wall with rectangular interval towers. The inner walls rose to the height of 25 meters (82 ft.) and were equipped with vaulted galleries and arrow slits at two different levels. In the interior there were a chapter house and chapel with ribbed vaulting, now incorporated into the houses of the town. The Templars held Tortosa until 3 August 1291, when it was finally abandoned, two months after the fall of Acre to the Mamlûks. The Templars held the small offshore island of Ruad (mod. Arwād, Syria) for the next ten years.