Antioch was an important city for the crusaders to capture as it would secure them supplies and reinforcements from the byzantine empire. Antioch was a formidiable citadel that the crusaders would have trouble taking.
Bohemond one of the main leaders of the first crusade was able to communicate with one of the crusaders inside the wall. This traitor was able to open the walls for the crusaders waiting on the other end the unprepared turks fought hard and in the chaos the city garrison leader Yaghi Siyan was killed. His son however managed to hold out in the city long enough for a massive turkish force to come to his aid. Led by Kerbogha of Mosul they laid siege to the crusaders on the inside of the citadel. On june 28th to the turks suprise the crusaders martched out of the city these crusaders massacred the cavalry. The cavalry had no chance as they only wore light gear for protection. Most of the remaining forces fled and Bohemond ran back into the city pronouncing himself prince of Antioch.