Guten Morgen, Majestät!!
House of Windsor
They are actually German.
In 1917 they Changed their name from
German Saxe-Coburg and Gotha to Windsor.
Wikepedia:
The House of Windsor is the reigning royal house of the United Kingdom and the other Commonwealth realms. In 1901, the House of Saxe-Coburg and Gotha (a branch of the House of Wettin) succeeded the House of Hanover to the British monarchy with the accession of King Edward VII, son of Queen Victoria and Prince Albert of Saxe-Coburg and Gotha. In 1917, the name of the royal house was changed from the German Saxe-Coburg and Gotha to the English Windsor because of anti-German sentiment in the United Kingdom during World War I.[1] There have been four British monarchs of the House of Windsor since then: George V, Edward VIII, George VI, and Elizabeth II.
Mountbatten (Prince Phillip)
They, too, were German and changed their name.
The Mountbatten family is a British dynasty originating as a cadet branch of the German princely Battenberg family. The name was adopted during World War I by members of the Battenberg family residing in the United Kingdom due to rising anti-German sentiment amongst the British public. The name is a direct Anglicisation of the German Battenberg (literally Batten Mountain), a small town in Hesse.
The family now includes the Marquesses of Milford Haven (and formerly the Marquesses of Carisbrooke), as well as the Earls Mountbatten of Burma. Prince Philip of Greece and Denmark, the consort of Queen Elizabeth II, adopted the surname of Mountbatten from his mother's family in 1947, although he is a member of the House of Schleswig-Holstein-Sonderburg-Glücksburg by patrilineal descent. Lady Louise Mountbatten became Queen Consort of Sweden, after having married Gustaf VI Adolf of Sweden.