Baybars went north to deal with Krak des Chevaliers after the death of Louis IX of France on 29 November 1270.

According to Ibn Shaddad, two days later the first line of defences was captured by the besiegers; he was probably referring to a walled suburb outside the castle's entrance.

[3] Rain interrupted the siege, but on 21 March a triangular outwork immediately south of Krak des Chevaliers, possibly defended by a timber palisade, was captured.

Baibars' army attacked through the breach and on entering the outer ward where they encountered the peasants who had sought refuge in the castle.

After a lull of ten days, the besiegers conveyed a letter to the garrison, supposedly from the Grand Master of the Knights Hospitaller in Tripoli which granted permission for them to surrender.