Fairfax A LIFE OF THOMAS, LORD FAIRFAX by John Wilson (Franklin Watts: $17.95; 215 pp., illustrated)

The English aristocracy has always idolized Cromwell and his revolutionaries. Even some of Cromwell’s best biographers have been aristocrats--Sir Charles Firth, Sir James Berry, most recently Lady Antonia Fraser--and as time passes, the Age of Cromwell seems to increase its appeal for England’s upper classes. The present Lord Moran is no exception. Born John Wilson, the eldest son of Baron Moran, he succeeded to the title in 1977. He has now written a biography of Sir Thomas Fairfax, the highest-ranking general of Parliament’s forces in the English Civil War and the soldier who defeated Charles I in the famous battle at Naseby.

It is a good biography: relatively brief, factually reliable, sharp in the delineation of its protagonist, elegantly written and never pedantic in the use of sources. It proceeds linearly from birth to death, weaving ribbons of facts into its 19 short chapters. And yet, compared to Wilson’s study of Sir Henry Campbell-Bannerman--a large book published in 1973--”Fairfax” is a disappointment because whatever its other virtues, it is neither original nor ambitious.

Campbell-Bannerman, the liberal British prime minister at the turn of this century, was then the staunchest champion of independence for South Africa. Unlike Fairfax, he was controversial in his own time and to later generations. When Wilson wrote about Campbell-Bannerman in 1973, there was no reliable biography of “CB,” as he was known on Downing Street. Wilson seized a good opportunity and instructed his readers about the statesman who gave the Transvaal its freedom.

The new life of Fairfax is a much less original book. Wilson repeats what every competent historian of the English Civil War has already said about the man whose distant cousin, the sixth Lord Fairfax, provides the name-source for Fairfax County, Va.

But what new things can be said about Fairfax’s life since M. A. Gibb published his biography of Fairfax in 1938? No major documents--printed or manuscript--have come to light since then. The innovations in historical understanding have not been made by biographers but by professional historians who have reconsidered Fairfax in the light of radical politics during the Revolution, or as the leader of Cromwell’s New Model Army. Mark Kishlansky’s solid study of the New Model Army represents such a breakthrough.

However, Fairfax-the-man remains appealing for the ways he enlisted his public and private life in the service of his country. Lady Antonia Fraser has captured his essence better than anyone. “He inspired much love and admiration among his contemporaries, including Cromwell, for the unusual combination of the sweetness of his temperament with the steel of his military prowess.” Privately, Fairfax was inward looking: pious, self-disciplined, ruminative, much affected by his wife’s inflexible Calvinistic religion. On the battlefield, his introspection was transformed into military prudence, and Fairfax compares with the greatest of soldiers in any age: Caesar, Nelson, Wellington, Eisenhower.

No doubt Fairfax inspired trust among ordinary English citizens, and the affection he aroused was responsible in part for Cromwell’s triumph over the king’s forces. We sometimes forget that in the past ideological revolutions took place on battlefields as well as in assembly halls. Yet the idea of Fairfax’s nobility of character is not a subject about which a biographer can dwell on at length. Our readership has different expectations from biography.

Today Fairfax is remembered because he was a soldier. However virtuous he may have been in private life, however devoted--as Wilson writes--”to his horses, his books and his flowers” in Yorkshire, ultimately it is Fairfax-the-soldier who is commemorated in books like this one. And I doubt that further historical research will ever change this record.

John Aubrey, England’s Boswell during the Civil War, who was an exact contemporary of Fairfax, may have said the last word. Noting how steadily Fairfax had protected the city of Oxford after the monarch’s Royalists were defeated there, Aubrey writes: “The first thing General Fairfax did was to set a good Guard of Soldiers to preserve the Bodleian Library.” Why? “He was a lover of Learning,” Aubrey reports, “and had he not taken this special care, that noble library had been utterly destroyed.” Aubrey is right: A great soldier is never barbaric, not even in the face of the enemy.

The English aristocracy may be ultimately more fascinated by good soldiers than by Cromwell and his men. The attraction helps to account for other biographies of soldiers by English aristocrats: Sir Arthur Bryant’s “Duke of Wellington,” Viscount Duff Cooper’s “Life of Earl Haig” (the commander of the British Armed Forces during the First World War), Sir Winston Churchill’s well-known biography of the Duke of Marlborough, and now, Lord Moran’s life of Fairfax.