The House of Windsor is the current Royal House of the United Kingdom and each of the other Commonwealth realms. The royal house was founded by George V by a royal proclamation in 1917. The House of Windsor remains one of the only dynasties to have ruled over lands on all continents of the world simultaneously. The current head of the House of Windsor is Elizabeth II, the reigning monarch over the Commonwealth realms.
Queen Victoria was married to Prince Albert of Saxe-Coburg and Gotha – son of Duke Ernst I of the small German duchy of Saxe-Coburg and Gotha. Her descendants were also members of the ducal family of Saxe-Coburg and Gotha, a minor branch of the thousand year old House of Wettin. Victoria's son, Edward VII, and, in turn, his son, George V, reigned as members of this house.
However, high anti-German sentiment amongst the people of the British Empire during World War I prompted the King and his family to abandon all titles held under the German Crown, and to change German sounding titles and house names to English sounding versions. Hence, on 17 July 1917, a Royal Proclamation issued by George V provided that he and all his agnatic descendants would be members of the House of Windsor, with the personal surname Windsor if they did not have a title. The name had a long association with royalty, through the town of Windsor and Windsor Castle, a link reflected in the Round Tower of Windsor Castle being the basis of the badge of the House of Windsor. On the same day, Prince Louis of Battenberg adopted the surname Mountbatten, which is the literal translation into English. Prince Louis is the maternal grandfather of The Duke of Edinburgh.
Upon hearing that his cousin had changed the name of the British royal house to Windsor, German Emperor Wilhelm II remarked jokingly that he planned to see Shakespeare's play The Merry Wives of Saxe-Coburg-Gotha. The two cousins were photographed riding horses together in 1910 in at the funeral of George's father, Edward VII (Photo of Kings 1910), and again at Potsdam Palace three years later.(Photo of Kings 1913)
When Queen Elizabeth married Prince Philip of Greece and Denmark, the standard practice would be to adopt his family household name. Because he was a prince, Prince Philip did not have a surname but he was of the House of Schleswig-Holstein-Sonderburg-Glücksburg, a minor brach of the House of Oldenburg. Not wishing to repeat the difficulties of three decades ago, before his marriage Prince Philip renounced his titles and adopted the surname, Mountbatten, which his maternal grandfather had created in 1917.
In her British Privy Council, on 9 April 1952, Queen Elizabeth II officially declared her "Will and Pleasure that I and My children shall be styled and known as the House and Family of Windsor, and that my descendants who marry and their descendants, shall bear the name of Windsor."[1]. On 8 February 1960, the Queen confirmed that she and her children would continue to be known as the House and Family of Windsor, as would any agnatic descendants who enjoy the style of His/Her Royal Highness, and the title of prince or princess.[1] Still, Elizabeth also decreed that her agnatic descendants who do not have that style and title would bear the surname Mountbatten-Windsor,[1].
Any future monarch can change the dynastic name through a similar royal proclamation, but it is not anticipated that HRH The Prince of Wales will change the name of the royal family.