The Sumerians were the first people to migrate to Mesopotamia, they created a great civilization. Beginning around 5,500 years ago, the Sumerians built cities along the rivers in Lower Mesopotamia, specialized, cooperated, and made many advances in technology. The wheel, plow, and writing (a system which we call cuneiform) are examples of their achievements.
1 In a Parliamentary System, the head of state is usually a different person than the head of government (not in every country). 2  The HOG is often vested with more official power, but holds that position for a relatively short time.
A parliamentary republic is a type of republic which operates under a parliamentary system with no clear cuts seperation of powers between the executive and legislative branches In contrasts to republics operating under either the presidential system or the semi-presidential system, the head of the state usually does not have broad executive powers as a executive president would because many of those powers have been granted to a head of government.