(Heb. "Yahweh judges"), in the Bible, son of Asa, and king of Judah, in the 9th century B.C. During his period close relations subsisted between Israel and Judah; the two royal houses were connected by marriage (see ATHALIAH; JEHORAM, 2), and undertook joint enterprise in war and commerce. Jehoshaphat aided Ahab in the battle against Benhadad at Ramoth-Gilead in which Ahab was slain (1 Kings xxii.; 2 Chron. xviii.; cf. the parallel incident in 2 Kings viii. 25-29), and trading journeys to Ophir were undertaken by his fleet in conjunction no doubt with Ahab as well as with his son Ahaziah (2 Chron. xx. 35 sqq.; I Kings xxii. 47 sqq.). The chronicler's account of his war against Moab, Ammon and Edomite tribes (2 Chron. xx.), must rest ultimately upon a tradition which is presupposed in the earlier source (i Kings xxii. 47), and the disaster to the ships at Ezion-Geber at the head of the Gulf of Akaba preceded, if it was not the introduction to, the great revolt in the days of Jehoshaphat's son Jehoram, where, again; the details in 2 Chron. xxi. must rely in the first instance upon an old source. Apart from what is said of Jehoshaphat's legislative measures (2 Chron. xix. 4 sqq.; cf. the meaning of his name above), an account is preserved of his alliance with Jehoram of Israel against Moab (2 Kings iii.), on which see JEHORAM; MoAB. The "valley of Jehoshaphat" (Joel iii. 12) has been identified by tradition (as old as Eusebius) with the valley between Jerusalem and the mount of Olives. (S. A. C.)