Complex sentence: In December of 1271, as Baybars was battling the Mongols in Aleppo the Crusader forces of King Edward raided Qaqun, but were quickly fought back by Mamluk emirs.
Split into simpler sentences: In December of 1271, as Baybars was battling the Mongols in Aleppo the Crusader forces of King Edward raided Qaqun. They were quickly fought back by Mamluk emirs.