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.

Philip and Elizabeth were both royal by birth, both great-great-grandchildren of Queen Victoria, but, in temperament and upbringing, they were two very different people. The Queen's childhood was loving and secure, the Duke's was turbulent; his grandfather assassinated, his father arrested, his family exiled, his parents separated when he was only ten. Elizabeth and Philip met as cousins in the 1930s. They married in 1947, aged twenty-one and twenty-six.

Philip: The Final Portrait tells the story of two contrasting lives, assesses the Duke of Edinburgh's character and achievement, and explores the nature of his relationships with his wife, his children and their families - and with the press and public and those at court who were suspicious of him in the early days. This is a powerful, revealing and, ultimately, moving account of a long life and a remarkable royal partnership.