Elah was the son and successor of Baasha. The Bible records only one incident from Elah's two year reign: his chariot commander Zimri staged a military coup while Elah was off getting drunk!
Zimri, one of his officials, who had command of half his chariots, plotted against him. Elah was in Tirzah at the time, getting drunk in the home of Arza, the man in charge of the palace at Tirzah. Zimri came in, struck him down and killed him in the twenty-seventh year of Asa king of Judah. Then he succeeded him as king.
(1 Kings 16:8-10)
As soon as he was seated on the throne, Zimri killed off Baasha's whole family, thus ending Israel's second dynasty and fulfilling the prophecy of Jehu.