Syrian soldiers have raised the national flag on the battlements of a 900-year-old Crusader castle after a three-month siege that ended yesterday when rebel fighters fled.

The recapture of Crac des Chevaliers, a Unesco World Heritage site, is a real and symbolic victory over divided rebel factions.

The army has also wrested back control of most of al-Hosn, the town below the hilltop castle, which was surrounded by Syrian troops for weeks until many rebels moved out yesterday and the army moved in, according to residents.

“The Syrian Arab Army raised the national flag on al-Hosn Castle in Homs province after eliminating the terrorists holed up in it,” Syrian state TV said.

This is the best example of medieval Syrian castle architecture

The army’s siege of Crac des Chevaliers echoes the tactic used by the Mamluke Islamic dynasty in the 13th century against Crusaders in the fortress.

The Syrian army’s advance is part of a campaign to secure towns along the Lebanese border as well as a highway from the capital Damascus to the coast that is vulnerable to rebel attack.

The castle is one of the best preserved in the world but suffered mortar hits as rebels sheltered behind its thick stone walls, built for battles hundreds of years ago.

“Crac des Chevaliers is the best example of medieval Syrian castle architecture. It has a unique importance for the area,” said Konrad Hirschler of the University of London.

Syria’s three-year-old conflict has devastated whole city neighbourhoods and ancient sites including Aleppo’s medieval covered market and Umayyad mosque. Looting has threatened tombs in the desert town of Palmyra and Roman temples have been damaged.

Dozens of wounded Syrian rebels fleeing al-Hosn were ambushed as they attempted to cross a river into Lebanon yesterday.