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 system is a system of government in which the ministers of the executive branch are drawn from and accountable to the legislature, such that the executive and â¦ legislative branches are intertwined. In such a system, the head of government acts as de facto chief executive and chief legislator.n contrast to a presidential republic and the semi-presidential system, the head of state usually does not have broad executive powers as an executive president would, because much of those powers have been granted to a head of government (usually called a prime minister).