Prince Harry married Meghan Markle in a stunning ceremony on Saturday, May 19 at St George's Chapel, in Windsor.

However, although the Suits star may have married her Prince Charming, she won't be a princess - the couple now have the title of Duke and Duchess of Sussex.

Given to them by his grandmother The Queen, Harry now has the highest rank in the British peerage but if the couple have children, will they be princes and princesses, like their dad?

It may not be the case, reports the Birmingham Mail, unless a change is made to the law.

Harry's great-great-grandfather King George V limited titles within the royal family when he issued a Letters Patent in 1917.

It read: "...the grandchildren of the sons of any such Sovereign in the direct male line (save only the eldest living son of the eldest son of the Prince of Wales) shall have and enjoy in all occasions the style and title enjoyed by the children of Dukes of these Our Realms."

Prince Harry and Meghan Markle leave St George's Chapel after their wedding
Prince Harry and Meghan Markle leave St George's Chapel after their wedding

This means Harry and Meghan's children, should they have any while Elizabeth II is on the throne, will not be HRHs or princes or princesses, but will be known instead as Lord or Lady (forename) Mountbatten-Windsor.

However the Queen could issue a new Letters Patent to change this - just as she did for the Duke and Duchess of Cambridge's children.

George was always entitled to be HRH Prince George of Cambridge as the eldest son of the eldest son of the Prince of Wales. But HRH Princess Charlotte of Cambridge would have been Lady Charlotte Mounbatten-Windsor.

In December 2012, when Kate was around three months pregnant, the Queen issued a Letters Patent under the Great Seal of the Realm declaring "all the children of the eldest son of the Prince of Wales should have and enjoy the style, title and attribute of royal highness with the titular dignity of Prince or Princess prefixed to their Christian names or with such other titles of honour".

A Letters Patent was granted in 1948 just before the Prince of Wales's birth because the 1917 decree excluded Princess Elizabeth's children from taking a royal style and title.

The Princess Royal's children, Peter and Zara Phillips, who do not hold titles, were Master and Miss Phillips when they were born. They were not entitled to be HRHs under the 1917 decree as they were born down the female line.

The Earl and Countess of Wessex's children, Lady Louise Mountbatten-Windsor and Viscount Severn, are actually entitled to be a princess and prince as children of the son of the Sovereign.

But Edward and Sophie decided, with the Queen's agreement, that their children would use the courtesy titles of sons or daughters of an earl rather than the style prince or princess.