He was the son of Sennacherib. He killed his father Sennacherib and fled.
Isa 37:38While he was worshiping in the temple of his god Nisroch, his sons Adrammelech and Sharezer killed him with the sword, and they escaped to the land of Ararat. And his son Esarhaddon succeeded him as king.
2 Kgs 19:37While he was worshiping in the temple of his god Nisroch, Adrammelech and Sharezer struck him down with the sword, and they escaped to the land of Ararat. And his son Esarhaddon succeeded him as king.