Leader and Government
The current ruler of england is Queen Elizabeth II (Top right image).
This means that she is the figure head of the country but holds a limited power over the country.
The official with the most power is the prime minister who is in charge of the government.
The current prime minister is David Cameron (Center image) who is also the leader of the conservative party in England.
Also, England has something similar to the US Supreme Court called Parliament. It's members act like the Supreme Courts members and review every act done by the royal family and David Cameron in order to see that the country is run to the best of its' abilities.