 Macrinus and his son , weakened by the desertion of the Second Legion due to bribes and promises circulated by Julia Maesa , were defeated on 8 June 218 at the Battle of Antioch by troops commanded by Gannys . Macrinus fled toward Italy , disguised as a courier , but was later intercepted near Chalcedon and executed in Cappadocia . His son Diadumenianus , sent for safety to the Parthian court , was captured at Zeugma and also put to death . 
