As they retreated, Alexius was separated from his guard and was attacked by Norman soldiers. While escaping he was wounded in his forehead and lost a lot of blood, but eventually made it back to Ohrid, where he regrouped his army.[23]
In OTL, Robert Guiscard had to return to Italy because Henry IV, Holy Roman Emperor, had attacked the Pope at Alexios' suggestion. In Guiscard's absence, Alexios reconquered the territory they had lost to the Normans.
So what if Alexios didn't escape? Could a Norman state be set up in Greece? Would it last, or would it just be reconquered by the next emperor?