2 Kings 8:16
And in the fifth year of Joram the son of Ahab king of Israel, Jehoshaphat being then king of Judah, Jehoram the son of Jehoshaphat king of Judah began to reign.
Cross-reference
In 2 Kings 8:25, Ahaziah son of Jehoram becomes king — continuing the dynasty introduced here.
In 2 Kings 3:1, Joram began his reign in Israel — here his fifth year dates Jehoram's accession in Judah.
In 2 Kings 1:17, Jehoram of Judah is synchronized to Joram's second year — here it's the fifth year, suggesting a coregency.
In 2 Kings 9:29, Ahaziah's accession is dated to Joram's eleventh year — a later synchronism in the same line.
In 2 Chronicles 21, Jehoram's wicked reign and death are detailed — this verse introduces that same king.
In Matthew 1:8, Jehoram appears in Jesus' genealogy — bridging this OT king to the NT Messiah.
In 1 Kings 22:50, Jehoshaphat dies and Jehoram succeeds him — here Jehoram already reigns, indicating a coregency.
In 1 Kings 22:42, Jehoshaphat's age and 25-year reign are recorded — this verse references him as still reigning.