Reign and reforms
Succeeding his father Asa, Jehoshaphat undertook comprehensive religious reform. In the third year of his reign he sent priests and Levites throughout the cities of Judah to instruct the people in the Law, and he sought to remove the high places dedicated to false worship. The biblical chronicler presents his rule as combining religious devotion with effective governance.
He also established a judicial order, appointing judges in the fortified cities of Judah and setting up a court of appeal in Jerusalem, with care taken to keep ecclesiastical and secular jurisdictions distinct. His reign is remembered as a period of relative peace and prosperity for the kingdom.
Alliances and the victory at Ein Gedi
Jehoshaphat pursued alliance with the northern Kingdom of Israel, sealed through the marriage of his son Jehoram to Athaliah, daughter of King Ahab. He accompanied Ahab to the siege of Ramoth-Gilead, a venture for which he was rebuked by the prophet Jehu son of Hanani.
The most celebrated episode of his reign was an invasion by a coalition of Moabites, Ammonites, and others who encamped at Ein Gedi. Facing the threat, Jehoshaphat prayed in the Temple, confessing the kingdom's powerlessness before so great a host. The Levite Jahaziel prophesied deliverance, and according to the account the allied armies fell into confusion and destroyed one another, so that Judah gathered the spoils without battle.
Commemoration among the Forefathers
Jehoshaphat is venerated in the Orthodox Church among the Holy Forefathers, the Old Testament patriarchs, prophets, kings, and righteous men and women who are the ancestors of Christ according to the flesh. This company, extending from Adam through the royal line of Judah to the Theotokos and John the Forerunner, is commemorated together on the Sunday of the Holy Forefathers, the Sunday falling between December 11 and 17 in the period of the Nativity Fast.
A distinct individual veneration of Jehoshaphat is not clearly attested; he is honored chiefly within this collective commemoration of the ancestors of Christ. His place there rests on his inclusion in the genealogy of the Gospel of Matthew and on the scriptural portrait of him as a king who trusted in the Lord.