2 Kings 14:23 (ESV)

23 In the fifteenth year of Amaziah the son of Joash, king of Judah, Jeroboam the son of Joash, king of Israel, began to reign in Samaria, and he reigned forty-one years.

This king Jeroboam is known as Jeroboam II, as the first king of the ten-tribe kingdom also had that name (see 1 Kings 12:20). They were not related, as Jeroboam II came from another dynasty. As his contemporary and colleague in Judah, Azariah, he reigned for a long time, which indicates prosperity and success (see more in 2 Kings 14:25). There are only seven verses about Jeroboam II, but that does not mean much. He reigned longer than any other ruler of the northern kingdom, and much happened under his rule (see 2 Kings 14:23–29 where his life is briefly presented).