King Jehu and the Northern Kingdom of Israel
The Bible mentions that king Jehu was an evil king, he did not seek God with all his heart, he was an idolater, he made Israel to sin. He reigned for 28 years.
King Jehu was an officer in Ahab’s bodyguard. It was Elisha who anointed him to be king and to cut off Baal worship in Israel, and to cut off the house of Ahab. Jehu was the man for the task, he was devoted to this bloodshed showing no mercy. He slew Jehoram king of Israel, Jezebel, Ahaziah king of Judah (son-in-law of Ahab) and his brothers, Ahab’s 70 sons, and all friends of Ahab’s house. He destroyed all the temples of Baal and any worshippers and priests.
But king Jehu "did not depart from the sins of Jeroboam, and took no heed to walk in the law of God." God used a wicked man to destroy wicked people.
Read more about king Jehu in:
2 Kings Chapter 9
2 Kings Chapter 10
During this time Hazael king of Syria took over Gilead and Bashan of the land of Israel in the east of the Jordan River. Assyria was starting to move westward in their war campaigns and collecting tribute from anyone un-submissive.
Assyrian annals mention contacts with some ten Hebrew kings: Omri, Ahab, Jehu, Menahem, Hoshea, Pekah, Uzziah, Ahaz, Hezekiah, and Manasseh.
During the reign of Hoshea, king of Israel, Shalmaneser V, king of Assyria, invaded Israel (2 Kings 17:3,5) and attempted to destroy the kingdom that remained. In 722 BC Shalmaneser V died and his successor Sargon II besieged and took Samaria, carrying away 27,290 of the population as he tells in his Khorsabad Annals. Later Assyrian kings, particularly Esarhaddon (681 BC - 668 BC), completed the task.
2 Kings 10:31
But Jehu took no heed to walk in the law of the LORD God of Israel with all his heart; for he did not depart from the sins of Jeroboam, who had made Israel sin.
"And the period that Jehu reigned over Israel in Samaria was twenty-eight years."