Prince Philip, the husband of Queen Elizabeth, was never called King Philip when his wife assumed the throne in February 1952 because of a royal protocol.

According to reports, this protocol dictated that when a man marries into the royal family, he won't be able to carry the male form of his blood royal wife's title. This is the same situation with Princess Beatrice and Princess Eugenie's husbands, Edoardo Mapelli Mozzi and Jack Brooksbank, who did not become princes when they married the York sisters.

Philip could also not be called the King or King Consort when Elizabeth became the Queen as the King is deemed the highest position in the social hierarchy of the British royals.

When Philip and Elizabeth, then the Princess of York, married in 1947, he was gifted a title by his father-in-law, King George VI. He was called Your Royal Highness but he was not titled as Prince. He was also named the Duke of Edinburgh, as well as the Earl of Merioneth and Baron Greenwich.

However, as the husband of the monarch, Philip did get an official role as the prince consort, without the title attached. The only person to use such a title in the history of the British royal family is Prince Albert. He married Queen Victoria, the grand matriarch of the European royal family and the grandmother of both Philip and Elizabeth, who are actually third cousins.

Philip is a blood prince of Greece and Denmark, as the son of Prince Andrew and Prince Alice. But when he married Queen Elizabeth, he had to become a British subject, which meant that he had to renounce his claims to the throne of Greece and Denmark. Five years after his wife's rule as the monarch, she granted him the title of Prince and since then, his official title became His Royal Highness The Prince Philip, Duke of Edinburgh.

The royal never made any comments on why he's not king. He was more upset when his children did not belong to the House of Mountbatten, his real family name. The British royal family is known as the Windsors, after Queen Elizabeth's family.

More than a decade into their marriage, Queen Elizabeth made a declaration that the male heirs of her family, who did not have any title, would use Mountbatten-Windsor. Thus, this is the name in the birth certificate of Archie Harrison, the son of Prince Harry and Meghan Markle. (Business Times)