2 Kings 10:1-7, 11

Ahab had seventy sons [and grandsons] in Samaria. So Jehu wrote letters and sent them to Samaria, to the rulers of Jezreel, to the elders, and to the guardians of the children of Ahab, saying, “Now as soon as this letter comes to you, since your master’s sons (male descendants) are with you, as well as chariots and horses and a fortified city and weapons, select the best and most capable of your master’s sons, and set him on his father’s throne, and fight for your master’s [royal] house.” But they were extremely afraid and said, “Look, the two kings did not stand before Jehu; so how can we stand?” And the one who was in charge of the household, and the one who was overseer of the city, the elders, and the guardians [of the children] sent word to Jehu, saying, “We are your servants and we will do whatever you tell us, but we will not make any man king; do what is good in your eyes.” Then Jehu wrote a second letter to them, saying, “If you are with me and will obey me, take the heads of your master’s sons, and come to me at Jezreel tomorrow about this time.” Now the [dead] king’s sons, seventy persons, were with the great men of the city, who were rearing them. When the letter came to them, they took the king’s sons and slaughtered them, seventy persons, and put their heads in baskets, and sent them to Jehu at Jezreel.

So Jehu killed all who remained of the house of Ahab in Jezreel, and all his great men and his familiar friends and his priests, until he left him without a survivor.