It was a big moment for a little royal, as he made his debut on the balcony of Buckingham Palace to help celebrate his great-grandmother's official birthday.
At just over a year old, Prince Louis more than rose to the occasion as he charmed the world with his first, very enthusiastic, royal wave.
The third child of the Duke and Duchess of Cambridge pointed to the fly-past overhead, waved at crowds below and politely clapped the national anthem as he the stole the show at Trooping the Colour, where the Royal family turned out to honour the Queen and her Armed Forces.