Ahab had 70 sons, so Jehu sent letters to their schoolmasters and butlers and guardians and ordered that they choose the most likely son to send against him to fight for claim to the kingdom. But the masters and guardians were all, Uh, we’d rather not. So Jehu sent another message saying, If you want to show your loyalty to me and save your own lives, send me the heads of Ahab’s sons. So they did, which Jehu took as a sign from God he was meant to be king.
Then Jehu issued a proclamation that he was going to hold a festival for Baal and that all the followers and priests of Baal needed to attend. When everybody was squeezed into the temple, he locked the doors and ordered his men to kill all inside. Then they burned the temple. God was pleased with Jehu’s initiative that It sent him a message that It would guarantee Jehu and his progeny would rule in Israel for at least four generations.
For the most part, times were peaceful, but unfortunately, King Hazael of Syria started capturing and conquering the edges of Israelite territory.