Harold Macmillan, By Charles Williams

Enoch Powell declared that all political careers end in tears. Of few is this more true than Harold Macmillan. The all-conquering Supermac of Vicky's Evening Standard cartoon had become by the end, an almost pathetic figure, a pastiche of Edwardian grandeur, an apparent hedonist and antique poseur who confessed during the Profumo affair that he did not move among young people very often. Howard Brenton's play, Never so Good, along with Jeremy Irons's masterly stage performance, captured precisely the tragedy of a great career blighted by wartime injury and domestic unhappiness, overtaken by a new world he never quite understood.

It is time for a reappraisal and Charles Williams's biography is a fine achievement, fair in tone and spare in style. A Labour peer, he has previously written sympathetic biographies of other right-wing figures such as de Gaulle, Petain and Adenauer. In his first venture into British history, he displays rather less affection for his subject.

An abundance of quotes shows how much Macmillan was disliked by contemporaries such as Churchill, Eden and Butler. Some thought him a pompous pedant, others "deeply unpleasant"; to Lord Salisbury he was just "a twister". The US ambassador David Bruce almost echoed AJP Taylor's verdict on Lloyd George – "He had no friends and did not deserve any."

But there were always positive aspects. Williams well illuminates the influence of his private tutor Ronald Knox on Macmillan's Anglo-Catholic morality. He also rightly emphasises his vulnerability. Often plunged into emotional turmoil, Macmillan was far from "unflappable". In particular, the long-term infidelity and cruelty of his wife, Dorothy, Bob Boothby's mistress, wore him down.

The book brings out four particular points. First there was Macmillan's crucial and ever-growing role as Minister Resident in Algeria from 1942. In addition to being involved in Italy and Greece, Macmillan's intelligent diplomacy with Eisenhower and the Americans helped de Gaulle to establish himself as Free French leader and return home a national icon. Second, Williams has fascinating new material on the Suez crisis. While confirming Macmillan's deviousness in switching from chief hawk to advocate of retreat ("first in, first out", in Harold Wilson's words), Williams shows that his claim that the US was undermining sterling by leading a run on the pound was totally untrue. Third, Williams spells out the complexity of Macmillan's triangulation in diplomacy, envisaging a British central role in Europe while maintaining a "special" relationship with the Americans, and a "Grand Design" based on an ultimately abortive nuclear collaboration with de Gaulle. Finally, Macmillan's downfall is powerfully dissected. It was the Night of the Long Knives, not Profumo's amorous nights, which did for him. As with Gordon Brown, reshuffle was the reflection of defeat.

Macmillan made key errors during his career. He was too optimistic in handling de Gaulle, on the basis of their wartime collaboration; Churchill thought Macmillan "too pro-French". As housing minister, he helped to distort the national finances and lowered standards of house-building from those enforced by Nye Bevan.

He greatly over-estimated his status in the Anglo-American alliance, as his marginalisation over Cuba in 1962 showed. Dean Acheson's famous remark about Britain seeking a role was a mordant comment on Macmillan's classical delusions about playing Greece to America's Rome. Finally, Macmillan landed party and country with Alec Douglas-Home, not Rab Butler, as prime minister, a lamentable choice.

Yet Macmillan's career was manifestly one of achievement. His premiership (from 1957 to 1963) brought real domestic success until mid-1961; his Britain was a more prosperous and civilised country. He skilfully rebuilt trust with the Americans after the serial lying of Suez. He was also, for all his innate Balliol-based Englishness, a pioneer of relations with Europe from the Schuman Plan onwards, a statesman of frequent vision and idealism.

He helped phase out the old empire with little violence and without tears; the "wind of change" speech in South Africa and retreat from the Central African Federation compared well with French debacles from Algeria to Indochina. Clem Attlee claimed that, but for the war, Macmillan, not himself, could have been Labour's post-war prime minister. This thoroughly absorbing book chronicles the tragic Odyssey of an almost great man.

Kenneth Morgan's updated 'Oxford Illustrated History of Britain' has recently been published by OUP