2 Kings 10:1-7, 11

Now there were in Samaria seventy sons of the house of Ahab. So Jehu wrote letters and sent them to Samaria: to the officials of Jezreel, to the elders and to the guardians of Ahab’s children. He said, “You have your master’s sons with you and you have chariots and horses, a fortified city and weapons. Now as soon as this letter reaches you, choose the best and most worthy of your master’s sons and set him on his father’s throne. Then fight for your master’s house.” But they were terrified and said, “If two kings could not resist him, how can we?” So the palace administrator, the city governor, the elders and the guardians sent this message to Jehu: “We are your servants and we will do anything you say. We will not appoint anyone as king; you do whatever you think best.” Then Jehu wrote them a second letter, saying, “If you are on my side and will obey me, take the heads of your master’s sons and come to me in Jezreel by this time tomorrow.” Now the royal princes, seventy of them, were with the leading men of the city, who were rearing them. When the letter arrived, these men took the princes and slaughtered all seventy of them. They put their heads in baskets and sent them to Jehu in Jezreel.

So Jehu killed everyone in Jezreel who remained of the house of Ahab, as well as all his chief men, his close friends and his priests, leaving him no survivor.