The King’s playboy younger brother was a womaniser who overestimated his abilities, whose indiscretions saw him put in lockdown on the Windsor Estate, and who ended up at the centre of a blizzard of conspiracy theories. No, not Andrew Mountbatten-Windsor, but Prince George, the Duke of Kent. Prince George, who was born in 1902 as the fourth son of George V and Queen Mary, was said to have been Princess Elizabeth’s favourite uncle. As a distant “spare” behind Edward VIII, George VI and the Duke of Gloucester, he was able to combine service with hedonism. He joined the Navy and...