Adam Clarke on 1 Kings 11:24

And reigned in Damascus - Rezon was one of the captains of Hadadezer, whom David defeated. It seems that at this time Rezon escaped with his men; and; having lived, as is supposed, some time by plunder, he seized on Damascus, and reigned there till David took Damascus, when he subdued Syria, and drove out Rezon. But after Solomon's defection from God, Rezon, finding that God had departed from Israel, recovered Damascus; and joining with Hadad, harassed Solomon during the remaining part of his reign. But some think that Hadad and Rezon were the same person.