The Duke and Duchess of Cambridge have named their daughter Charlotte Elizabeth Diana.
The fourth in line to the throne will be known as Her Royal Highness Princess Charlotte of Cambridge, Kensington Palace announced.
She was born on Saturday in the Lindo Wing of London's St Mary's Hospital weighing 3.7kg.
The Queen and other senior royals were told of the baby's name before the announcement was made public.
A Kensington Palace official, when asked by the BBC about the couple's choice of name, said: "We'll let the names speak for themselves."
Charlotte, the feminine form of Charles, has a long royal pedigree and became popular in the 18th century when it was the name of George III's queen.
The King bought Buckingham House in 1761 for his wife Queen Charlotte to use as a family home close to St James's Palace - it became known as the Queen's House and is now Buckingham Palace.
Charles is the name of two former Kings and of the Prince of Wales, the princess's grandfather.
Charlotte also has more recent connections for the royal couple. On the duchess's side, it is the middle name of her sister Pippa Middleton and on the duke's it is the name of his cousin Charlotte Spencer, Earl Spencer's youngest daughter.
The earl tweeted his approval.
Perfect names. My 2-year old Charlotte Diana will be thrilled at cousinly name-sharing. Is at an age where thinks world revolves around her!— Charles Spencer (@cspencerbooks) May 4, 2015
The choice of middle names honours the baby's late grandmother, Diana, Princess of Wales, and her great-grandmother Queen Elizabeth.
Charlotte has been the most popular girls' name in New Zealand for the past two years. Last year 255 baby girls were given the name and 303 were registered as Charlotte in 2013.
- BBC / Reuters / RNZ