The UK's Queen Elizabeth celebrated 70th wedding on Monday with her husband Prince Philip. She was 21 when she walked down the on November 20, 1947. She is the British monarch to celebrate a platinum anniversary. She is also the UK's longest reigning . The spent the day at a small private at their home - Windsor Castle. They marked the occasion with a set of official . Britain's post office also celebrated the anniversary with a set of commemorative stamps.
The royal couple met as teenagers during World War II. Prince Philip was the son of a Greek . He gave up his title to marry the then Princess Elizabeth. Before his wedding, he told his mother-in-law that he had, "fallen in completely" with her daughter. He said: "My job first, and last, is never to let the Queen down." The Queen has always relied on her . She described him as her "". A former BBC explained that helped their marriage. She said: "A big of what has kept them going…is the fact they can share a together."