England fans departing for the World Cup in Germany this summer might want to put this major reappraisal of the country's greatest football manager in their flight bags.

On the 40th anniversary of England's 1966 World Cup victory, award-winning author Leo McKinstry provides a fascinating portrait of this unique figure in his new book, which is out on April 3.

Until now, the story of Sir Alf has never been properly told, with his character seen as distant and enigmatic.

Through the depth of his research, the author has provided the first comprehensive biography of Ramsey.

Based on testimony from more than 100 interviews, McKinstry's book gives new insights into many different aspects of the manager's life, from his impoverished upbringing as the son of a Dagenham labourer, to his sad end when he was crippled by financial worries and Alzheimer's disease.

There are revelations about the nature of Sir Alf's marriage to a divorce, his unpopularity with some of his fellow players at Southampton and Spurs, and his difficult relationship with the press and the Football Association.

For the first time, the truth is disclosed about England's sorry campaign in Mexico in 1970, when team spirit was disrupted by the presence of certain players' wives, and about the sacking of Sir Alf in 1974, masterminded by his bitter enemy, Prof Harry Thompson.

Among those interviewed are Sir Tom Finney, Alan Ball, Peter Shilton, Nobby Stiles, Sir Trevor Brooking, Ray Wilson, Francis Lee, and Alan Mullery.

There are a number of uplifting passages throughout the book, particularly on the remarkable victory in 1966, and on the devotion that Sir Alf inspired in his squads.

McKinstry, who wrote the best-selling biography of Jack and Bobby Charlton in 2003, employs his readable style to build a vivid profile of this shy, passionate and gifted man.

Sir Alf, Leo McKinstry, (HarperSport, £18.99)