Sumer's location as the southernmost region of Mesopotamia, along with its access to the Persian Gulf, made it a prime location for a blossoming of culture and economy. Many believe that the Sumerian city of Uruk is where civilization began.
A few dynasties have appeared in Sumer over the course of its history. The First Dynasty of Lagash started around 2500 B.C. This small empire included the majority of Sumer as well as some parts of Elam.
Another dynasty—the Third Dynasty of Ur—is remembered as occurring during a period of time when the Sumerian Renaissance influenced many aspects of Sumerian life. Cultural advancements were the goal of the kings during this period, thus a peace was maintained that allowed for advancements in technology and art to blossom. The advancements that occurred at this time helped the area to be remembered as the cradle of civilization.