Prince Phillip was of Greek royal ancestry, not German. The Georges I to IV were German, and then William IV (1830-37) continued the Hanover line (he was like George IV a son of George III). Victoria (1837-1901) was the daughter of another son of George III. Edward VII who became king in 1901 was Victoria’s eldest son (fathered by another German noble, Prince Albert of Saxe-Coburg and Gotha).
So up until 1910 the throne was essentially Germanic in origin. It remained that way because George V (1910-36) was the eldest son of King Edward VII and his wife who was of Danish royal origins. The name of the House changed as it follows the paternal line, from Hanover to Saxe-Coburg and Gotha. Anti-German sentiment in WW-I (in 1917) forced a change in name to the House of Windsor, otherwise Elizabeth would have been a Saxe-Coburg not a Windsor. The practice of following the paternal line changed also so that Charles III remains a Windsor and not whatever Phillip’s Greek royal house may have been.
Such fine idle chatter on a boring Sunday afternoon. LOL
Prince Phillip had the surname Mountbatten and has links to several German and Danish royal houses with multi-hyphenated titles, and bore the general title Prince of Greece and Denmark within that.
Some lesser members of the royal family have the surname Mountbatten-Windsor, but the Queen took the idea of the “House of Mountbatten” out of existence by royal proclamations early in her reign. Apparently Philip’s father thought the monarchy should become the House of Mountbatten.