Queen Elizabeth gave birth to Prince Charles in November 1948.
The Prince of Wales' arrival was celebrated with traditional pomp and ceremony via an announcement from Buckingham Palace and a gun salute to mark the birth of the heir to the British throne, Express.co.uk reports.
But while the UK was electrified by the news, Prince Philip "casually" met his newborn son and flatly declared that he looked like a "plum pudding".
According to 2013 Netflix documentary The Royals, the Duke was playing squash when Charles was born and took his time before visiting the child, getting a "quick swim" in first.
Royal author Philip Dampier said: "After the game of squash, [he] rushed upstairs to see his newborn son and just said to the Queen, 'he looks like a plum pudding'."