Great Britain’s Prince Philip, the husband of Queen Elizabeth, is dead at the age of 99. The Duke of Edinburgh was the longest-serving spouse of a reigning British monarch. He was born into Greek and Danish royalty, but his family was exiled from Greece when he was a baby. Prince Philip joined Britain’s Royal Navy in 1939 and it was that year he began corresponding with young Princess Elizabeth. He adopted the family name Mountbatten when he became a naturalized British subject in 1947. Later that year he would marry Elizabeth, who became Queen of England in 1952.