As Elizabeth's husband, Prince Philip acts officially as the sovereign's consort and accompanies her to various official events — like the opening of Parliament. Because of England's rules about royalty, no man who marries a queen (or future queen) can be given the title of "King of England," unlike women who marry kings and future kings. Despite originally being born a Prince of Greece and Denmark, Philip had to give up his old royal titles when he became a naturalized British citizen before he married Elizabeth in 1947. However, in 1957, the queen restored his previous royal status by giving him the title of Prince of the United Kingdom. In addition to his consort duties, Philip also oversees the running of the queen's two private estates — Balmoral and Sandringham — and serves as the ranger for Windsor Great Park at Windsor Castle.
Prior to becoming the queen's consort, Philip served with the Royal Navy and worked his way up to becoming Commander of the Frigate HMS MAGPIE. He also served during World War II. However, Philip was forced to give up his naval career once Elizabeth became queen.