Prince Harry and Meghan Markle: Will marriage make the actress a princess?

Meghan Markle will not be called Princess Meghan when she ties the knot with Prince Harry next year.

By the standards of British royal protocol, the former Hollywood star lacks "royal blood".

This means Meghan will follow Catherine Middleton’s suit of becoming Her Royal Highness, Princess Harry of Wales.

Royal blood means that the Queen's late sister Margaret was entitled to call herself Princess Margaret. By that logic, the Queen's daughter became Princess Anne and her granddaughters are called Princess Beatrice and Princess Eugenie.

Sarah Ferguson, however, was never Princess Sarah and Sophie Rhys-Jones - the wife of Prince Edward - is not Princess Sophie.

According to the same rule, Lady Diana Spencer was never officially Princess Diana. She was the Princess of Wales and, after her divorce from Prince Charles, she was Diana, Princess of Wales.

Prince Harry is the latest member of the royal family to tie the knot with a 'commoner.' 

His wedding with American actress girlfriend Meghan Markle will take place in Spring 2018, Clarence House confirmed on Monday.

The couple were engaged in London earlier this month and Prince Harry has informed The Queen and other close members of his family. The prince also sought and received the blessing of Meghan Markle's parents.

The couple will reside in Nottingham Cottage at Kensington Palace.