=Extent of David's Empire.= The conquest of the Ammonites and the Moabites and the defeat of the Arameans enabled David to extend the bounds of his empire to the desert. In the northeast it probably never extended beyond Mount Hermon, which was its natural boundary in that direction. In the south he fought a decisive battle with the Edomites in the Valley of Salt, which was probably at the southwestern end of the Dead Sea near the border line between southern Judah and Edom. This Arab race, in its difficult mountain fastnesses, was held in control by means of Hebrew garrisons established throughout the land. By this means David's southern boundary was extended to the eastern arm of the Red Sea and the Sinaitic Peninsula, thus attaining in every direction its natural barriers. In less than one generation, as a result of the energy, tact, and broad statesmanship of David, the physical limitations of Palestine were overcome and a strong empire was established along the southeastern Mediterranean. =Absalom's Rebellion.= As later events quickly proved, however, the unity of the Hebrew Empire was chiefly dependent upon the personal charm and ability of the man who built it up. The discordant elements were still present and only required an opportunity to break forth into a flame of civil war. Absalom, inspired by a treasonable ambition, succeeded in winning away the affections of the southern tribes and in stirring up the rivalry between the north and the south. This rivalry was traceable not only to racial differences, but to the fundamental variations between the physical environment and contour of Northern and Southern Israel. It was natural that Absalom's rebellion should be launched in Hebron, the old capital of David's kingdom. In fleeing from the rebels David aimed to put between himself and them that great natural barrier, the Jordan valley, which separates Palestine into its two great divisions. Among the hills and deep wadies of the land of Gilead he felt most secure. Here he was in the midst of a prosperous people, intensely loyal to a ruler whose wars and victories had at last given them immunity from the attack of their strong foes. This part of Palestine was least swayed by the passions of the hour and most loyal to its deliverer. Here also David could rally his followers, without identifying himself with the tribes of the north, as opposed to those of the south.