2 Kings 15:23

In the fiftieth year of Azariah king of Judah, Pekahiah the
son of Menahem began to reign over Israel in Samaria
As it was in the thirty ninth of Azariah that his father began his reign, and he reigned ten years, they must end in the forty ninth of Azariah, and therefore there must be an interregnum of a year; perhaps the title of Pekahiah might be disputed, and it was a year before he could get settled on the throne:

and reigned two years;
being slain by one of his captains, as after related.