Jason of Pherae (in Greek, Ιάσων των Φερών), was the ruler of Thessaly during the period just before Philip II of Macedon came to power. He was appointed tagus, or king, of Thessaly in the 370s BC and soon extended his control to much of the surrounding region. Controlling a highly-trained mercenary force as well as the famous Thessalian cavalry, Jason briefly transformed Thessaly into a powerful Greek state and even spoke of invading the Persian Empire. Before writing to Philip II, Isocrates sent letters to Jason requesting that he unify Greece--as Philip later would. However, he was assassinated in 370, so one can only question his political and military ambitions. His son, Alexander, inherited the title of tagus and ruled harshly before finally being defeated by the Thebans.
