We take a look back at photos of the prince, from his schoolboy years, through his love story with the Duchess of Cambridge, to his latest role as a father.
1. Family
The Duke of Edinburgh, Prince Edward, Queen Elizabeth II, Princess Anne, the Prince of Wales holding Prince Harry, the Princess of Wales, and Prince William on the balcony of Buckingham Palace, London, in 1985
2. School days
Prince Harry, five, joins his brother Prince William, seven, on his first day at the Wetherby School in Notting Hill, West London in September 1989.
3. Day out with mum
The Princess of Wales and her two sons Prince Harry and Prince William leaving London's Natural History Museum in 1992
4. Three generations
Three generations of the royal family posing for a photograph at Clarence House in 2003 before a dinner to mark the 50th anniversary of the Queen's Coronation.