Son of Asa; he became king of Judah about 873 BCE and reigned for twenty-five years (1 Kgs. 15: 24; 2 Chron. 20: 31) as the contemporary of Ahab of Israel (1 Kgs. 22), with whom he formed an alliance against Syria. The prophet Micaiah tried to dissuade the two kings from fighting, but they ignored his advice and Ahab (though he disguised himself in Jehoshaphat's robes) was slain. The account is rewritten by the Chronicler (2 Chron. 18) in the light of his theology; Jehoshaphat is praised for his piety and rewarded with a substantial victory over Ammonites and Moabites (2 Chron. 20: 1–30).