The passage is parenthetic, resuming the history of the kingdom of Judah from 1 Kings 22:50.
The opening words are - “In the fifth year of Joram, son of Ahab, king of Israel, and of Jehoshaphat, king of Judah;” but they contradict all the other chronological notices of Jehoshaphat 1 Kings 22:42, 1Ki 22:51; 2 Kings 3:1; 2 Chronicles 20:31, which give him a reign of at least twenty-three years. Hence, some have supposed that the words “Jehoshaphat being then king of Judah,” are accidentally repeated. Those, however, who regard them and 2 Kings 1:17 as sound, suppose that Jehoshaphat gave his son the royal title in his 16th year, while he advanced him to a real association in the empire seven years later, in his 23rd year. Two years afterward, Jehoshatphat died, and Jehoram became sole king.
The “eight years” are counted from his association in the kingdom. They terminate in the twelfth year of Johoram of Israel.
Jehoshaphat’s alliance, political and social, with Ahab and Ahab’s family had not been allowed to affect the purity of his faith. Jehoram his son, influenced by his wife, Athaliah, the daughter of Ahab, “walked in the way of the kings of Israel;” he allowed, i. e., the introduction of the Baal-worship into Judaea.
Among the worst of Jehoram’s evil doings must be reckoned the cruel murder of his six brothers 2 Chronicles 21:4, whom he killed to obtain their wealth.
The natural consequence of Jehoram’s apostasy would have been the destruction of his house, and the transfer of the throne of Judah to another family. Compare the punishments of Jeroboam 1 Kings 14:10, Baasha 1 Kings 16:2-4, and Ahab 1 Kings 21:20-22. But the promises to David (marginal references) prevented this removal of the dynasty; and so Jehoram was punished in other ways 2Ki 8:22; 2 Chronicles 21:12-19.