Sumer
Sumer () is the earliest known civilization in the historical region of southern Mesopotamia, modern-day southern Iraq, during the Chalcolithic and Early Bronze ages, and one of the first civilizations in the world along with Ancient Egypt and the Indus Valley. Living along the valleys of the Tigris and Euphrates, Sumerian farmers were able to grow an abundance of grain and other crops, the surplus of which enabled them to settle in one place. Prehistoric proto-writing dates back before 3000 BC. The earliest texts, from c. 3300 BC, come from the cities of Uruk and Jemdet Nasr; early cuneiform script emerged around 3000 BC.
Dilmun
The Dilmun civilization was the centre of commercial activities linking traditional agriculture of the land—then utterly fertile due to artesian wells that have dried since, and due to a much wetter climate—with maritime trade between diverse regions such as the Meluhha (Indus River Valley), Magan (Oman), and Mesopotamia. The Dilmun civilization is mentioned first in Sumerian cuneiform clay tablets dated to the late third millennium BC, found in the temple of goddess Inanna, in the city of Uruk. The adjective Dilmun is used to describe a type of axe and one specific official; in addition there are lists of rations of wool issued to people connected with Dilmun.