With the Queen starting to dial down her royal duties in the lead up to her Platinum Jubilee, many people are looking toward the future when her eldest son Prince Charles becomes king.
The prince has been the first heir to the throne for seven decades, making him the longest-reigning heir in the British monarchy - during which time he's always been known as Prince Charles, the Prince of Wales.
While you might assume that he will one day become King Charles, there is a chance that he could end up being called a different name entirely.
