The king of Assyria in 714 and 713 B.C. was Sargon (B.C. 721-705). If then the Biblical and Assyrian chronologies which agree exactly in the year of the taking of Samaria (721 B.C.), are to be depended on, the king of Assyria here must have been Sargon. It may be conjectured that he had taken offence at something in the conduct of Hezekiah, and have threatened Jerusalem about this time (compare Isaiah 20:6). There is, however, no evidence of actual hostilities between Judaea and Assyria in Sargon’s reign.
Related Commentaries of 2 Kings 20:6
2 Kings 20:6
6 And I will add unto thy days fifteen years; and I will deliver thee and this city out of the hand of the king of Assyria; and I will defend this city for mine own sake, and for my servant David's sake.