At the time of their empire, their capital and central fortress was Khatti, which lay to the east of the Halys, on the Anatolian plateau some three thousand feet above sea-level. It occupied a strong position near the crossing of the great lines of traffic through Asia Minor; and expansion from this area must have begun to take place at an early period beyond the west bank of the river, where the country offered greater facilities for pasturage. Another line of advance was southward to the coast-plains beneath the Taurus, and it is certain that Cilicia was occupied by Hittite tribes before any attempt was made on Northern Syria. That at first the Hittites were scattered, without any central organization, among a number of independent city-states, may be inferred from their later records. For when a land is referred to in their official documents, it is designated "the country of the city of so and so," suggesting that each important township had been the centre of an independent district to which it gave its name. Some of the Hittite states attained in time to a considerable degree of importance. Thus we find Tarkundaraba of Arzawa sufficiently eminent to marry a daughter of Amen-hetep III. of Egypt.[32] Another city was Kussar, one of whose kings, Khattusil I., was the father of Shubbiluliuma, under whom the Hittites were organized into a strong confederacy which endured for nearly two hundred years. It must have been owing to its strategic importance that Shubbiluliuma selected Khatti as his capital in place of his ancestral city.