12th-dynasty king of Egypt (ruled 1878-1843 BC) who completely reshaped Egypt´s government and extended his dominion in Nubia the land immmediately south of Egypt.
During the reigns of his predecessors the provincial nobles of Middle Egypt had enhanced their power through royal favours and intermarriage with the families of neighbouring potentates.
Around the middle of Sesostris III´s reign the rich provincial tombs which were a mark of the nobles´ power abruptly ceased to be built.
Simultaneously the memorials of middle class persons increased at Abydos, the Upper Egyptian shrine of the popular god Osiris.
As shown by documents of the next dynasty Sesostris III strengthened the central government shearing the feudal nobility of their power and influence.
Egypt was divided into three great districts, one from the Delta to the capital in the Fayyum above Cairo, the second from the capital to Thebes and the third from Thebes to the southern border.
Each of these departments possessed a hierarchy of officials and scribes directly responsible to the vizier.
Additionally the vizier possessed a ministry and countrywide departments of treasury, agriculture, war and labour resources were created.
These assumed governmental functions and kept strict accounts of income and disbursement.
So effective were the reforms that in the following dynasty, in spite of weak rulers, the central government under the viziers continued to function effectively for over a century.
Sesostris III´s second great achievement was his overhaul and extension of Egypt´s Nubian possessions.
Probably responding to raids by the tribes of western Nubia which were endangering trade with the African hinterland, the king conducted four campaigns in which he quelled the nomads and extended the frontier to between the Second and Thir Nile cataracts.
Next he rebuilt several forts of the series erected by his predecessors in LOwer Nubia and added three in the freshly acquired territory.
These, plus four others, either completely rebuilt or newly founded, formed a network within signalling distance of one another, extending from the new frontier to the central fort at Buhen at the Second Nile Cataract.
The new forts displayed advanced construction techniques and were admirably suited to the terrain.
The king left orders that no southerners should pass the outermost forts except for trade or as emissaries and then pass only to the first fort above Buhen where a trade depot existed.
Dispatches from the next reign show that the orders were strictly followed and both river traffic and nomads in the desert were screened and observed.
Nile inundation heights also were recorded at the forts giving valuable advance notice to Egypt proper.
Before his first Nubian campaign in year eight, Sesostris cut a canal through the First Nile Cataract at Elephantine thus easing the passage of both military and commercial shipping.
Probably after his Nubian campaigns Sesostris conducted a minor foray into Palestine advancing to Shechem.
Inscriptions of the king´s officials reveal that miners were busy at Sinai and at several places in Nubia.
Within Egypt he built a fine temple at Naj´al Madamud near Thebes in Upper Egypt.
The king built his pyramid near his grandfather´s but incorporated the innovations of his father´s tomb.
In the complex fine sets of two princesses´ jewelry were recovered.
It was partly the exploits of this king, partly those of his two like-named predecessors and also deeds of Ramses II of the 19th dynasty which came to figure in the legend of Sesostris that Herodotus recorded.
The name Sesostris derived from Senwosret, presents no linguistic difficulties.
Moreover Sesostris III´s memory long outlived him for he became the patron deity of Egyptian Nubia.
Ramses II accounted for the Asiatic conquests of the legend and the rest was heroic elaboration.