The period before recorded history in Egypt and before it became a unified state in c 3100 BC. The term predynastic denotes the period of emerging cultures that preceded the establishment of the 1st dynasty in Egypt. In the late 5th millennium BC there began to emerge patterns of civilization that displayed characteristics deserving to be called Egyptian. The accepted sequence of predynastic cultures is based on the excavations of Sir Flinders Petrie at Naqadah, al-'Amirah (el-'Amra), and al-Jazirah (el-Gezira). Another somewhat earlier stage of predynastic culture has been identified at al-Badari in Upper Egypt. Until recently, most of our knowledge of pre-Dynastic Egypt was derived from the excavation of graves. Pre-Dynastic communities appeared in the section of the Nile Valley immediately south of Asyut. Large settlements were established, notably that at Hierakonpolis. Some time after 5000 BC the raising of crops was introduced, probably on a horticultural scale, in small, local cultures that seem to have penetrated southward through Egypt into the oases and the Sudan. The food-producing economy was based on the cultivation of emmer wheat and barley and on the herding of cattle and small stock, together with some fishing, hunting, and use of wild plant foods. Highly specialized craftsmen emerged to build vessels, make copper objects, weave linen, and make basketry and pottery. A series of small states arose until around 3100 BC, the unified kingdom of Ancient Egypt came into being.