The Tribe of Ephraim was one of the Twelve Tribes of Israel, named for Ephraim, the son of Joseph. The tribe entered the land of Canaan during its conquest by Joshua and formed part of a loose confederation of Israelite tribes, and Ephraim joined the other northern Israelite tribes in making King David of Judah ruler of the United Kingdom of Israel. During the reign of Rehoboam, the Tribe of Ephraim split off from the House of David to form the Kingdom of Israel. The Ephraimites were massacred by Jephthah's Gileadites, and they were part of the Kingdom of Israel until its conquered by Assyria in 723 BC.