Living along the valleys of the Tigris and Euphrates rivers, Sumerian farmers grew an abundance of grain and other crops, a surplus which enabled them to form urban settlements.
The world's earliest known texts come from the Sumerian cities of Uruk and Jemdet Nasr , and date to between c. Most historians have suggested that Sumer was first permanently settled between c. Others have suggested that the Sumerians were a North African people who migrated from the Green Sahara into the Middle East and were responsible for the spread of farming in the Middle East. Some scholars associate the Sumerians with the Hurrians and Urartians , and suggest the Caucasus as their homeland.
Based on mentions of Dilmun as the "home city of the land of Sumer" in Sumerian legends and literature, other scholars have suggested the possibility that the Sumerians originated from Dilmun, which was theorized to be the island of Bahrain in the Persian Gulf.
A prehistoric people who lived in the region before the Sumerians have been termed the " Proto-Euphrateans " or " Ubaidians ", [ 36 ] and are theorized to have evolved from the Samarra culture of northern Mesopotamia. They drained the marshes for agriculture , developed trade, and established industries, including weaving , leatherwork , metalwork , masonry , and pottery. Some scholars contest the idea of a Proto-Euphratean language or one substrate language; they think the Sumerian language may originally have been that of the hunting and fishing peoples who lived in the marshland and the Eastern Arabia littoral region and were part of the Arabian bifacial culture.
The Sumerian city of Eridu , on the coast of the Persian Gulf, is considered to have been one of the oldest cities , where three separate cultures may have fused: that of peasant Ubaidian farmers, living in mud-brick huts and practicing irrigation; that of mobile nomadic Semitic pastoralists living in black tents and following herds of sheep and goats; and that of fisher folk, living in reed huts in the marshlands, who may have been the ancestors of the Sumerians.
