His remarkable energy, resilient consitution and strong sense of public duty have served Prince Philip well over the course of his 64-year marriage to the Queen.

But it is his policital incorrectness and public gaffes that he is most well known for.

The Duke celebrates his 90th birthday tomorrow and we select the pick of what the Prince himself describes as 'Dontopedalogy . . . the science of opening your mouth and putting your foot in it, a science which I have practised for a good many years . . .'