Prince William and his wife Kate Middleton, the Duchess of Cambridge, on Friday named their baby son Louis Arthur Charles, Kensington Palace said.
In a statement, the palace said: “The Duke and Duchess of Cambridge are delighted to announce that they have named their son Louis Arthur Charles. The baby will be known as His Royal Highness Prince Louis of Cambridge.”
Prince Louis, who was born on Monday, is the third child of the Royal couple, the younger brother to Prince George and Princess Charlotte.
The name of the prince is announced after four days of his birth.
Prince Louis is fifth in line to the throne, behind his grandfather Prince Charles, father Prince William, brother Prince George and sister Princess Charlotte.
The name of the newborn prince honours both Prince’s grandfather, Prince Charles, and great grandfather Louis Mountbatten, the Duke of Edinburgh’s mentor who was killed by an IRA bomb in 1979.
On Monday, William, the 35-year-old Duke of Cambridge, was present at the birth of his boy, who weighed 3.82 kg at the time of birth.
The 36-year-old Duchess of Cambridge was admitted on Monday to the Lindo Wing of St Mary’s Hospital in London, where both her previous kids George in 2013 and Charlotte in 2015 were also born.
A change in the law after William and Kate were married in April 2011 gave female heirs the same rights of accession to the throne in the UK as men.