An (Sumer)
An and Ninhursag were probably the progenitors of the other gods in the Sumerian pantheon. His wife may have been Nammu.
An - Sumerian God An
An is a Sumerian progenitor god.
Uruk
Uruk was an important early city of southern Mesopotamia, which is known today, as Warka, and in Biblical literature, as Erech.
Mesopotamia Religion
Information on the beginning of religion and its hold on Mesopotamia.
An
From Christopher Siren's page. An may have been the main god of the pantheon before 2500 BC. He and Ninhursag were probably the progenitors of the other gods.