The new royal baby is the first Prince of Cambridge to be born for more than 190 years.
The last was Prince George of Cambridge, a grandson of George III and the only son of Prince Adolphus Frederick, the 1st Duke of Cambridge.
Prince George of Cambridge was born in 1819 and refused to have an arranged marriage. He wed a commoner for love after falling for the actress Sarah Louisa Fairbrother, who was said to be a classic beauty and a graceful dancer.
They married in 1847 when she was already the mother of two of his children and pregnant with his third.
But the Duke did not seek the sovereign's approval and the marriage was never recognised, hence his children were not eligible to inherit royal titles.
Miss Fairbrother was ostracised by the Royal Family and never given a title. Instead she became known by the nickname Mrs FitzGeorge and this surname was taken by George's offspring.
Despite his marriage, George had a wandering eye and soon after he wed he took up with mistress Louisa Beauclerk, who remained his lover for more than 30 years.
He went on to become the 2nd Duke of Cambridge after his father's death.
The Duke was in the Army and served in the Crimean War. He was promoted to Commander-in-Chief in 1887 and an equestrian statue of him stands in the middle of London's Whitehall.
He was said to have been a disciplinarian, who believed army promotions should be based on social connections rather than ability. He died in 1904.
His father, the 1st Duke of Cambridge - who lived from 1774 to 1850 - was never a Prince of Cambridge, but was given the title the Duke of Cambridge by his father George III in 1801 when he was 27.
