In 1939, King George VI and Queen Elizabeth toured the Royal Naval College, Dartmouth. During the visit, the Queen and Earl Mountbatten asked Philip to escort the King's two daughters, Elizabeth and Margaret, who were Philip's third cousins through Queen Victoria, and second cousins once removed through King Christian IX of Denmark.[28] Elizabeth fell in love with Philip and they began to exchange letters.[29] Eventually, in the summer of 1946, Philip asked the King for his daughter's hand in marriage. The King granted his request, provided that any formal engagement was delayed until Elizabeth's twenty-first birthday the following April.[30] By March 1947, Philip had abandoned his Greek and Danish royal titles, had adopted the surname Mountbatten from his mother's family, and had become a naturalised British subject.[fn 2] The engagement was announced to the public on 10 July 1947.[31] The day preceding his wedding, King George VI bestowed the style His Royal Highness on Philip, and on the morning of the wedding, 20 November 1947, he was made the Duke of Edinburgh, Earl of Merioneth, and Baron Greenwich of Greenwich in the County of London.[32] Philip and Elizabeth were married in a ceremony at Westminster Abbey, recorded and broadcast by BBC radio to 200 million people around the world.[33] However, in post-war Britain, it was not acceptable for any of the Duke of Edinburgh's German relations to be invited to the wedding, including Philip's three surviving sisters, all of whom had married German princes, some of them with Nazi connections. After their marriage, the Duke and Duchess of Edinburgh took up residence at Clarence House. Their first two children were born: Prince Charles in 1948 and Princess Anne in 1950. Philip was keen to pursue his naval career, though aware that his wife's future role as queen would eventually eclipse his ambitions. Nevertheless, Philip returned to the navy after his honeymoon, at first in a desk job at the Admiralty, and later on a staff course at the Naval Staff College, Greenwich.[19] From 1949, he was stationed in Malta, after being posted as the first lieutenant of the destroyer HMS Chequers, the lead ship of the 1st Destroyer Flotilla in the Mediterranean Fleet.[34] In July 1950, he was promoted to lieutenant commander and given command of the frigate HMS Magpie.[35] He was promoted to commander in 1952,[19] but his active naval career ended in July 1951.[36][37] In 1960 he joined The Castaways' Club, having been introduced by his first cousin David Mountbatten, 3rd Marquess of Milford Haven, which enabled him to keep in close contact with many of his naval contemporaries.[citation needed] With the King in ill health, Princess Elizabeth and the Duke of Edinburgh were each appointed to the Privy Council on 4 November 1951, after having made a coast-to-coast tour of Canada. At the end of January the following year, Philip and his wife set out on a tour of the Commonwealth. On 6 February 1952, when they were in Kenya, Elizabeth's father died so she became Queen. It was Philip who broke the news of her father's death to Elizabeth at Sagana Lodge, and the royal party immediately returned to the United Kingdom.[38]