 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.Reliable historical records begin much later; there are none in Sumer of any kind that have been dated before Enmebaragesi (c. 26th century BC).