29 April 2011 Last updated at 08:23 GMT Kate will be Her Royal Highness the Duchess of Cambridge after she takes her vows
Prince William has been made the Duke of Cambridge and his wife will become Her Royal Highness the Duchess of Cambridge, after their wedding, Buckingham Palace says.
He will also take the titles Earl of Strathearn and Baron Carrickfergus.
The royal groom was given the titles by his grandmother, the Queen, to mark his marriage.
The title of duke is the highest rank in the British peerage.
The three titles link the couple to England, Scotland and Northern Ireland.
Giving new titles to members of the Royal Family on their wedding day is a long-standing tradition.
When Prince Andrew married, he became the Duke of York, Earl of Inverness and Baron Killyleagh.
Prince Edward became the Earl of Wessex and Viscount Severn on his wedding day in 1999.
While the Prince of Wales did not take any additional titles when he married Lady Diana Spencer in 1981, he was already Prince of Wales, the Duke of Cornwall, Duke of Rothesay, Earl of Carrick, Baron of Renfrew, Lord of the Isles and Prince and Great Steward of Scotland and Earl of Chester.
The Dukedom of Cambridge was created in 1801 but became extinct on the death of the 2nd Duke of Cambridge in 1904.'Doomed to failure'
Prince George, known as the 2nd Duke of Cambridge, was born in 1819 and was a grandson of George III and the only son of Prince Adolphus Frederick, the 1st Duke of Cambridge.
He served in the Crimean War and was promoted to commander-in-chief in 1887.
Indeed, once married, the newlyweds' carriage procession will pass a statue of the last duke sat on a horse close to the Ministry of Defence in Whitehall.
The 2nd Duke of Cambridge refused to have an arranged marriage and declared such unions were "doomed to failure".
He had an unrecognised marriage to actress Sarah Louisa Fairbrother in 1847, who at the time was already the mother of two of his children and pregnant with his third.'Mrs FitzGeorge'
But the Duke did not seek the sovereign's approval, the marriage was never recognised and Miss Fairbrother was never given the title the Duchess of Cambridge.
Instead she became known by the nickname Mrs FitzGeorge.
Strathearn has not been used as a title since the death of Alastair Windsor, the 2nd Duke of Connaught and Strathearn, who died in 1943.
By becoming Baron and Baroness Carrickfergus, the royal couple will be linked to County Antrim's oldest town.
An Irish Viscountcy of Chichester of Carrickfergus now held by the Marquess of Donegall was created in 1625 but Carrickfergus alone only existed as a title between 1841 and 1883.