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.
Despite the fact his first name is Charles, there's a chance the Prince of Wales could opt against using this name as his reigning moniker, because of the negative connotations surrounding previous kings also called Charles.
However, this is not as unusual as you might think, as many monarchs have chosen to change their name while on the throne - including the Queen's father Albert, who ascended the throne using the name his middle name, King George VI.
As the Prince of Wales' full name is Charles Philip Arthur George, he could opt to use any of the four as his regnal name, however, sources close to the prince previously claimed he was considering using his third middle name, George, meaning he would reign as King George VII.
Speaking to Studio 10 in 2005, former royal butler Grant Harrold said: "Normally royal children have two or three names. The reason is, if possibly that child was to become a king or queen, they have to have a kind of pool to choose from.
"For example, Prince Charles, if and when he becomes king, would be - people assume he would be Charles III. But he could technically be George VII because George is in his name."
If Charles were to choose his first name, he would reign as King Charles III, however, royal commentators predict he will decide against this due to negative connotations surrounding the two former King Charles.
Charles I, who became king in 1625, dismissed parliament three times and resolved to rule alone four years later. He reigned without a Parliament for more than a decade, a period which was dubbed 'eleven years' tyranny'.
Following two civil wars, Charles was tried and convicted of being a 'tyrant, traitor, murderer and public enemy to the good people of the nation' and was beheaded for treason on January 30, 1649.
His son, Charles II, lived in exile until he was crowned King of England, Ireland and Scotland in 1661.
He was popular and dubbed "the Merry Monarch", changing laws brought in by Oliver Cromwell and allowing people more freedom to enjoy themselves. However, he also lived a controversial lifestyle, fathering at least 14 illegitimate offspring.
It is unlikely Prince Charles will want to take on the moniker, however, we won't know for sure until he ascends the throne.
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