With the establishment of the Eleventh dynasty (_Ca._ 2160-2000 B.C.), the work of reuniting and re-establishing a centralized government began. The Delta had to be reclaimed from invaders who had gained the upper hand while the land was divided against itself. Unity being at last secured, rulers were free to launch out upon other enterprises. One of the later kings had a deep well provided for those who served in the quarries; another sent an expedition of 3,000 men to bring back stone for his tomb. These men were also instructed to go beyond the quarries--to Punt, which must have lain on the Somali coast of East Africa, and bring back products of that region. The expedition set out under the leadership of a nobleman whose report has fortunately come down to us. It states that his men built stations and made wells along their route, to the lasting benefit of those who might journey thence. Part of the detachment was left to quarry stone, while the rest proceeded to Punt and procured spices, gums, precious woods, and rare animals. After noting their safe return, the prince adds: "Never was brought down the like thereof for the king's court; never was done the like of this by any king's confidant sent out since the time of the god. I did this for the majesty of my lord because he so much loved me."[4] The Twelfth dynasty (2000-1788 B.C.) brought forth some of Egypt's ablest kings. Their creative ability was perhaps not excelled by subsequent pharaohs. Amenemhet I. (2000-1970 B.C.) proved himself strong enough to curb the power of the feudal princes. These hereditary nobles had probably received gifts of land from earlier kings in recognition of loyal service. The estates passed from father to son, and while the central government had been weak, the princes became more and more aggressive. They fortified themselves, each in his nome, retained large retinues of officials, servants, militia and realized vast incomes from extensive tracts of arable land. It was neither possible nor prudent to remodel the entire system, but Amenemhet I. undertook to modify it. Whenever one of these landed princes died, the king himself chose from the heirs the one who should succeed him. Naturally, he selected one whose loyalty to himself and to the government was unquestioned. Again, the boundaries of the nomes had never been officially determined, and during the years of confusion, strong nobles had infringed upon the possessions of weaker ones. The king made a tour through the country, heard all complaints of such encroachments, and decided the limits of all disputed boundaries. This did much to restrict the strength of ambitious princes. His son, coming to the throne, subdued the Nubians on the south and extended the empire to the second cataract; but it was left for Sesostris III. to make this conquest sure, and then to post his decree along the river.