important industries. Certain Kerma towns served to centralize agricultural products and direct trade. Analysis of the skulls of thousands of cattle interred in royal Kerma tombs suggest that stock were sometimes brought vast distances, from far districts, presumably as a type of tribute from rural communities on the death of Kerma's monarchs. This parallels the importance of cattle as royal property in other parts of Africa at later times. Only the centres of Kerma and Sai Island seem to have had contained sizable urban populations. Possibly further excavations will reveal other regional centres. At Kerma and Sai, there is much evidence of wealthy elites, and a class of dignitaries who monitored trade in merchandise arriving from far-off lands, and who supervised shipments dispatched from administrative buildings. Evidently, Kerma played an important intermediary role in the trade of luxury items from the Central African interior to Egypt. History Egyptian Old Kingdom epigraphic evidence, as well as evidence from Aniba (Nubia), indicate contacts with early Nubia at that time (2700–2200 BC), as well as the presence of early Nubian regional rulers. It appears that they were initially loyal to the kings of Egypt. The last mention in Sudan of an Old Kingdom of Egypt Pharaoh, Neuserre of the Fifth Dynasty was in 2400 BC Buhen, and the desert west of Toshka; no Egyptian presence occurs by the subsequent Sixth Dynasty. Regional contacts The Gash Group, a neolithic culture that flourished from 3000 to 1800 BC in Eritrea and the Eastern Sudan, had contacts with Kerma during the whole period of its development. Kerma elements occurred along the whole stratigraphic sequence at Mahal Teglinos, the main site of the Gash Group. For many centuries, the Gash people were included in the circuit of interchange between Egypt and the southern regions of the Nile valley, so Mahal Teglinos became an important commercial partner of the Kerma state. This trade activity clearly contributed to the rise of complex societies in the region. By 2300 BC, the Early C-Group culture was also appearing in Lower Nubia, most likely arriving from Dongola Reach (near Kerma). Thus, by the second millennium BC, Kerma was the centre of a large kingdom, probably the first in the Eastern Sudan, that rivelled Egypt. Egyptian Middle Kingdom period The Middle Kerma Period, coinciding with the Middle Kingdom of Egypt, continued from the reigns of Amenemhat I to Sobekhotep IV (c. 1990-1725 BC).