What does 2 Kings 1:2 mean?

After Ahaziah died, he had no son, so Jehoram became king in his place. This happened during Jehoram son of Jehoshaphat's reign in Judah. 2 Kings 1:2 - Modern Text Bible

(With no heir, the throne passes to another Jehoram, creating a confusing overlap of names between Israel and Judah.)