This is the story of Prince Philip, Duke of Edinburgh - the longest-serving consort to the longest-reigning sovereign in British history. It is an extraordinary story, told with unique insight and authority by an author who knew the prince for more than forty years. Philip - elusive, complex, controversial, challenging, often humorous, sometimes irascible - is the man Elizabeth II once described as her 'constant strength and guide'. Who was he? What was he really like? What is the truth about those 'gaffes' and the rumours of affairs? This is the final portrait of an unexpected and often much-misunderstood figure. It is also the portrait of a remarkable marriage that endured for more than seventy years.