God was appalled at the wickedness of Israel’s King Ahab and his family, and His instrument of punishment was one of Ahab’s military men, Jehu. God ordered the prophet Elisha to anoint Jehu king, and Jehu proceeded to wipe out (in brutal fashion) Ahab’s entire clan, including Ahab’s wicked wife, Jezebel, who was devoured by dogs. Jehu then tricked the worshippers of the false god Baal into a trap and killed them all. So Jehu destroyed Baal worship in Israel (2 Kings 10:28).
A “Jehu” has come to mean a fast and furious driver. This is based on 2 Kings 9:20: “The driving is like the driving of Jehu . . . for he driveth furiously” (KJV).