He is said to have given himself up to a life of wickedness, introducing many pagan and idolatrous customs (Isa. 8:19; 38:8; 2 Kings 23:12). He ignored the remonstrances and warnings of the prophets Isaiah, Hosea, and Micah, and appealed to Tiglath-Pileser III, the king of Assyria, for help against Rezin, king of Damascus, and Pekah, Prince of Israel, who threatened Jerusalem, This brought a great injury of his kingdom, and his own humiliating subjection to the Assyrians (2 Kings 16:7, 9; 15:29).
He died at the age of 35, after reigning 16 years, and was succeeded by his son Hezekiah. Because of his wickedness he was "not brought into the sepulchre of the kings."
By Divine direction, meeting Ahaz "at the end of the conduit of the upper pool, in the highway of the fuller's field," he bade him have no fear of "these two tails of smoking firebrands," Rezin and Pekah, for, like dying torches, they would speedily be extinguished (Isaiah 7:3 ff.).
The statement in 2 Kings 16:20 that Ahaz "was buried with his fathers in the city of David" is to be understood in the light of 2 Chronicles 28:27, that he was buried in Jerusalem, but that his body was not laid in the sepulchers of the kings of Israel.