GIASONE. - High priest (175–172 B.C.), brother of Onia III, whom he supplanted by infamous intrigues. His name was Jēhōšūa, to which he gave the Greek form 'Iášōw.
IV (v.) Epifane, obtaining from him, with the promise of considerable sums, the high priesthood and support for the Hellenization of Jerusalem. He officially introduced Hellenism into Jerusalem: he built a gymnasium; he encouraged the young to adopt Greek customs (II Mach. 4, 7-17). He persecuted the faithful Jews; he sent a delegation to the games at Tyre, with 300 silver drachmas for a sacrifice to Hercules! He received Antioco in Jerusalem with great pomp (II Mach. 4, 18-22). Shortly afterwards (172) he sent Antioco the agreed sums; the messenger, Menelao, even worse than he, betrayed and supplanted him, purchasing the high priesthood with 300 additional talents of silver. G. fled to Ammonitis (II Mach. 23-26). During Antioco’s second expedition into Egypt (168), when the false report of his death spread, G., with about 1,000 men, marched against Jerusalem; he compelled Menelao to shut himself up in the citadel and took fierce revenge upon his fellow citizens. “But he could not maintain himself and had to withdraw into Ammonitis and wander from country to country in search of refuge, until he died among the Spartans, execrated” (II Mach. 5, 5-10).