Kensington Palace revealed the baby's full name will be George Alexander Louis. William and Kate's baby will be known as Prince George and as third in line to the throne will one day be king.
Kensington Palace said in a short statement: 'The Duke and Duchess of Cambridge are delighted to announce that they have named their son George Alexander Louis.
'The baby will be known as His Royal Highness Prince George of Cambridge.'
By naming their son George - which is synonymous with British kings - it looks like the couple have followed tradition. However, royal sources say the baby's names are not supposed to be symbolic but that the couple genuinely like them.
GEORGE ALEXANDER LOUIS: A ROYAL NAME WHICH IS STEEPED IN TRADITION AND HISTORY
The name George is synonymous with British kings.
It has come to represent the continuity of the monarchy and remained the bookmakers' favourite in the name-guessing stakes from the moment Kate's pregnancy was announced.
Six King Georges have worn the crown throughout history since the German-born George I, the first Hanoverian king of Great Britain, acceded to the throne in 1714.
The first name of the last King George - George VI - was actually Albert and he was known to his family as 'Bertie' but he selected George - his fourth name - to use as Sovereign.
He was the much-loved father of the present Queen and the new Prince George of Cambridge's great-great grandfather. George VI chose George in honour of his father George V and to create the impression of stability after the scandal caused by the abdication of his brother Edward VIII.
The name means farmer or earth worker. It was the 12th most popular name for boys born in England and Wales in 2011.
St George, a fourth-century Christian martyr, is the patron Saint of England and represents honour, bravery and gallantry. The legend of George slaying a dragon and rescuing an innocent maiden is medieval.
There has only been one other Prince of Cambridge and he was also called George.
|Historic: The German-born George I, left, the first Hanoverian king of Great Britain, acceded to the throne in 1714 '' Mwaviona na viatu vyao lakini''|
|Relations: The first Prince George of Cambridge was a grandson of George III, pictured hapa''|
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, who generated much scandal including having a portrait painted in which she showed off her bare legs, 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.
|THE KING' GEORGE V''|
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.
This is popular in Scotland, where Alexander III was regarded as one of the country's greatest rulers.
In April this year, Willem-Alexander was sworn in as King of the Netherlands after the abdication of his mother, Queen Beatrix.
Henry VIII, who married six times and set up the Church of England to split from the Roman Catholic Church.
This name has deep significance in the Windsor family in honour of the Prince of Wales's favourite uncle Lord Louis Mountbatten, who was killed by the IRA in 1979.
Louis is the last of William’s three middle names.
TUMESHIRIKI NA KUKAGUA KWANZA KUTOKA DM''