Hamath was threatened by the growing power of Hadad-ezer, when a new force entered the field. Joab, the commander of the Israelitish army, was a consummate general, and the veterans he led had been trained to conquer. Ammon was easily crushed, and while its capital was closely invested the Israelitish troops fell upon the Aramæans in campaign after campaign. Victory followed victory; the forces of Zobah and its allies were annihilated, and the Aramæan states as far as Hamath and even the Euphrates became the tributaries of David. Wealth flowed into the royal treasury at Jerusalem; the cities of northern Syria were plundered of their bronze, and the yearly tribute of the subject states, as well as the proceeds of the desert trade, yielded an unfailing revenue to the conqueror. The attempt of Hadad-ezer to found an Aramæan empire had failed. But the empire of David was hardly longer lived. The murder of Joab, and the unwarlike character and extravagance of Solomon, brought about its downfall. Damascus revolted under Rezon; and though in the war that ensued Solomon succeeded in keeping the cities of Zobah which kept guard over the caravan road, it never returned to Israelitish rule. When the disruption of the Israelitish kingdom came after Solomon's death, the Aramæans rallied round the successors of Rezon. Damascus increased in strength, and at times laid northern Israel under tribute. Between the two kingdoms there was indeed constant intercourse, sometimes peaceful, sometimes hostile. Syrian merchants had bazaars in Samaria, where they could buy and sell, undisturbed by tolls and exactions, and Israelitish traders had similar quarters assigned to them by treaty in Damascus. "Damask couches" were already famous, and Ahab sent a contingent of 10,000 men and 2000 chariots to the help of Ben-Hadad II. in his war against Assyria. This Ben-Hadad is called Hadad-idri or Hadad-ezer in the Assyrian texts; Ben-Hadad, in fact, was a god, who was worshipped by the Syrians by the side of his father Hadad.