Answer:
Like her mother, Jezebel did befor her, she led God's people in Judah, now the southern kingdom, away from Him and to the worship of the false Phoenician god, Baal. To remain in power as queen mother after her son, King Ahaziah dies, she murders the entire male ascendacy line - except the baby son of Ahaziah, Joash, More info may be read in the book of 2 Kings and 2 Chronicles.