The prime minister.
There is a president too, but his position holds very few functions, completely unlike the position of President in America.
it is one of the most stable governments in the world
The head executive of a state government is called a governor.
The head executive of a state government is called the Governor.
The head of Germany's government is called the Federal Chancellor, or just Chancellor.
The head of government in Germany is called the Chancellor.
The head executive of the government in the United States is called the President. In some countries the head is the Prime Minister.
Chancellor
Monarchy
mayor
The head of New Spain was called a Viceroy.
The head of the parliamentary government is called the Prime Minister.
In most cases, the head of a municipal government is the position called "mayor".