Ernst August. The decree by the head of the House of Hanover is not legally recognised in the United Kingdom or Ireland, and the titles are used as titles of pretence. Since, however, the Hanovers are born in the male-line of George II, they were bound by the Royal Marriages Act 1772 until repealed in 2015. Thus, before his marriage to Princess Caroline of Monaco, Ernst August requested, and Queen Elizabeth II issued on 11 January 1999, an Order in Council: "My Lords, I do hereby declare My Consent to a Contract of Matrimony between His Royal Highness Prince Ernst August Albert of Hanover, Duke of Brunswick-Luneburg and Her Serene Highness Princess Caroline Louise Marguerite of Monaco..." Without the royal assent, the marriage would have been void in the United Kingdom. After the abdication crisis of 1936, King George VI issued letters patent (dated 27 May 1937) regranting his elder brother his style as son of a sovereign, whilst expressly denying the style of Royal Highness to his wife and descendants. The marriage, however, had no issue. On 22 October 1948, George VI issued letters patent allowing the children of his daughter Princess Elizabeth, Duchess of Edinburgh, and son-in-law Philip, Duke of Edinburgh, to assume princely titles and the style Royal Highness; they would not have been entitled to them ordinarily, as grandchildren in the female line, until their mother ascended the throne as Elizabeth II. Thus her son was styled HRH Prince Charles of Edinburgh until his mother's accession. Otherwise the children would have been styled Earl of Merioneth and Lady Anne Mountbatten, respectively. Elizabeth II issued letters patent, dated 22 February 1957, creating Philip, Duke of Edinburgh, a Prince of the United Kingdom of Great Britain and Northern Ireland. Prince Philip had been born a Prince of Greece and Denmark, titles he renounced upon going through the naturalisation process, unaware that he was already a British subject by virtue of the Sophia Naturalization Act 1705. On the wedding day of Prince Edward and Sophie Rhys-Jones, it was announced by Buckingham Palace that Elizabeth II, in agreement with their wishes, had declared that their children would be styled as children of an earl, and not as Princes of the United Kingdom with the style Royal Highness. On 31 December 2012, Elizabeth II declared that all the children of the eldest son of the Prince of Wales, at that time