Sesostris II, (flourished 19th century bce), king of ancient Egypt (reigned 1844–37 bce) of the 12th dynasty (1938–c. 1756) who devoted himself to the peaceful exploitation of Nubia, Egypt’s territory to the south, and initiated the development of Al-Fayyūm, a great oasis-like depression west of the Nile River and southwest of Cairo.
Following the established practice of his dynasty, Sesostris spent three years as his father’s coregent. In year 1 of this period, a trading expedition to Punt—on the east African coast—recorded its trip on the rocks at Egypt’s Red Sea port.
Early in Sesostris’s sole reign, the fortresses of Lower Nubia, built by the king’s grandfather, were inspected, and in year 6 the fort at Aniba, near the gold-mining region of Nubia, was rebuilt. As attested by commemorative stelae and inscriptions, diorite, copper, and possibly amethysts were extracted at a number of sites in Nubia. Inscriptions at Sinai indicate that the king’s miners were also active there.
Contacts with Palestine and Syria were also maintained, as is shown by the scene of Asiatic traders in a provincial tomb at Beni Hasan, in Middle Egypt. During this reign the noble family at this site increased its influence through intermarriage with neighbouring potentates.
Sesostris’s greatest achievement was his beginning of the development of Al-Fayyūm, the rich area near the royal residence. There, where the lake in Al-Fayyūm received its inflow from a branch stream off the Nile, the king constructed waterworks that were designed to regulate the lake’s level and partly reclaim the marshy ground around its shores. The project was later widely extended by Amenemhet III.
Nearby at Al-Lāhūn, Sesostris built his pyramid, which exhibits great craftsmanship; part of the workmen’s village has survived, yielding town-planning evidence and documents that reveal something of Egypt’s social conditions.