Jezebel was a Phoenician princess, daughter of Ethbaal, king of the Sidonians, who became queen of the northern kingdom of Israel through marriage to King Ahab. The Books of Kings frame the marriage as a political alliance that imported a foreign cult: Jezebel kept hundreds of prophets of Baal and Asherah at royal expense and moved to suppress the prophets of Yahweh, killing an unrecorded number, sparing only those Obadiah hid in caves. Her patronage of Baal set her against Elijah, whose career the text frames as a contest against her religious program.
That contest comes to a head at Mount Carmel, where Elijah challenges four hundred fifty prophets of Baal to a public test of whose god can send fire to consume a sacrifice. Baal sends nothing; Yahweh's fire consumes Elijah's soaked offering outright, and Elijah has the defeated prophets killed at the Kishon. Jezebel's response is a death threat sent to Elijah directly, which sends the prophet fleeing into the wilderness in despair, the only point in the cycle where Israel's most forceful prophet is shown outmatched by fear of her.
The second episode, the seizure of Naboth's vineyard, shows her operating through the machinery of state rather than open confrontation. When Ahab sulks because Naboth will not sell his ancestral land, Jezebel arranges false witnesses to accuse Naboth of cursing God and the king, has him stoned, and hands the vineyard to Ahab. Elijah confronts Ahab with a judgment naming Jezebel specifically: dogs will eat her flesh at Jezreel. The text delivers on that image in 2 Kings 9, where the general Jehu has her thrown from a window; her body is trampled by horses and eaten by dogs before it can be buried, leaving only her skull, feet and the palms of her hands.