House of Windsor.

The House of Windsor is the royal house of the United Kingdom and the other Commonwealth realms. It was founded by King George V by royal proclamation on 17 July 1917, when he changed the name of his family from the German Saxe-Coburg and Gotha(a branch of the House of Wettin) to the English Windsor, due to the anti-German sentiment in the British Empire during World War I. Currently, the most prominent member of the House of Windsor is its head, Queen Elizabeth II, the reigning monarch of each of the Commonwealth realms. The House of Windsor, as the British Royal Family, has the legal and constitutional prerogatives and practices associated with that status. 

Family tree.