The black-and-white footage shows the Queen, then aged six or seven, and her sister Margaret, around three, joining the Queen Mother and her uncle, Prince Edward, the Prince of Wales, in raising an arm in the signature style of the German fascists.

Edward, who later became King Edward VIII and abdicated to marry the American socialite Wallis Simpson, faced numerous accusations of being a Nazi sympathiser. The couple were photographed meeting Hitler in Munich in October 1937, less than two years before the second world war broke out.