Executive Leadership and Legislative Assemblies

The relationship between a head of government (head of the executive branch) and a nation's parliament or legislative assembly (the legislative branch) has long been the focus for comment and analysis - for example, has the prime minister in the United Kingdom come to a position of dominance at the expense of the power of parliament? Does the American president stand head and shoulders above Congress? Is a French president master of the system? Need the Russian president pay attention to the Dum