And while thousands cheered on the parade featuring soldiers and members of the Royal family in horse drawn carriages, one of the biggest stars of the day was chirpy Prince George.
The 2-year-old was snapped poking his tongue out, waving and clapping from a Buckingham Palace window during the parade through London.
Holding tight to the young monarch was his nanny, Maria Teresa Turrion Borrallo.
During George's cute display, his mother, the Duchess of Cambridge, was taking part in the parade; making her first official public appearance since the birth of her daughter last month.