In 1137, Byzantine emperor John II Comnenus arrived to impose Byzantine authority on Antioch, and promised Raymond of Antioch a principality consisting of Shaizar, Aleppo, Homs, and Hama if Antioch was returned to the Empire. In April 1138, the Byzantine army led the siege of Shaizar, but Raymond and Joscelin II of Edessa did not assist the emperor. Zengi soon arrived to relieve the fortress in May. The emir preferred Byzantine control to Zengid, and offered to recognize John as his overlord. Neither John or Zengi ever really enforced their authority there and Shaizar remained independent.