The Assyrian chief of staff tried to use intimidation to negotiate a peaceful settlement. In his first speech (Isaiah 36:4–10), he correctly argued that Egypt could not rescue them but incorrectly accused Hezekiah of misplaced trust in the Lord.
Interestingly, the Assyrian did not view the contest as between the gods of Assyria and the Lord, but rather between Sennacherib (the great king) and the Lord.