After forty years of reading and writing about the American past, I have reached one undebatable conclusion: history is full of surprises. Not many readers realize that historians are sometimes among the surprised. A book that seems relatively simple to create turns out to have hidden conflicts and unexpected insights into major characters that seldom appear in previous accounts of the drama. That is the story behind my new book on Valley Forge, which I think will surprise readers as much as it has surprised me.

As I began to research the subject, I assumed my theme would be the clash between history and memory. With over a dozen books on the American Revolution on my escutcheon, I already knew more than a little about Valley Forge. I looked forward to reporting on recent research that exploded myths about the freezing weather, the reasons for the soldiers' nakedness and starvation, and the ethnic composition of Washington's army.

The overarching drama, as I saw it, was still the stubborn endurance of Washington's soldiers and their emergence from the ordeal with their patriotism enriched by a new sense of solidarity. I hoped to enlarge this portrait with fresh, presumably vivid details.

As my files began to bulge with data from diaries and letters, archives and collections, the surprise began to emerge before my disbelieving eyes. There was another explanation for the Continental Army's survival at Valley Forge -- one that added an unexpected personal element to the story.

A new George Washington -- or at least a new side of this often oversimplified man -- gathered force and substance in my files. This Washington was not the long-suffering general who did little in the six months at Valley Forge but bemoan the condition of his starving half-naked army in letters to state governors and Continental congressmen. He was a man who confronted not only the threat of his army's collapse -- but the ruin of his reputation as a leader and a patriot -- and struck back at his enemies with ferocity and guile.

Even before his shoeless, shirtless, blanketless soldiers trudged to Valley Forge, General Washington was under savage attack by critics in the Continental Congress and in the upper ranks of his army. While the Americans headed for their barebones winter camp in the bleak hills, twenty miles away the British army was luxuriating in Philadelphia, the American capital that Washington had failed to defend.

More and more people concluded it was time to replace this fallen idol with a more reliable and experienced general. Long called the Conway Cabal after Thomas Conway, the Irish-born French trained general who was one of the loudest critics, in recent years it has been dismissed by many historians as much ado about not very much. One recent Washington biographer rechristened it "the Mifflin maneuver," after another more devious participant, General Thomas Mifflin, and also dismissed it.

I soon decided the dismissers missed the most important part of the story -- how Washington responded to these attacks, the way he identified and challenged or outmaneuvered his clandestine enemies and found allies in the Continental Congress. His performance began to evoke a word in my mind: politician. It troubled me at first. Washington is usually portrayed as a man who transcended politics. For too many Americans, politician connotes trickster, grandstander, schemer.

The political Washington who was emerging from my research was none of the above. He was a good politician in every sense of the word. Shrewd, tough when he needed to be, and adept at forming alliances with men like Henry Laurens, the president of the Continental Congress, who began as one of his critics.

Washington never lost sight of his goal, which was not a petty personal triumph over his adversaries -- but the rescue of his army, which he rightly saw as America's sole hope of victory in a long, bloody war. To achieve that aim, he had to outthink the naysayers who sought to destroy him and persuade others to outvote the congressional ideologues whose wrongheaded policies were the source of most of the Continental Army's woes.

In the end, Washington forced the name-callers to accept new men and new measures, selected and conceived by the embattled commander in chief. He also put an end to the slanderous campaign against his personal reputation, which was endangering the army almost as much as incompetence and ignorance in high places, most notably in the Continental Congress.

Washington's success in this secret war is all the more amazing because he achieved it while managing to keep the Continental Army from dissolving into mutiny and dispersal at Valley Forge. His political skills were bolstered by the power of his personality and his intelligence. This big Virginian not only looked like a leader, he understood and accepted leadership's responsibilities. In the embryonic free society he was helping to found, those responsibilities already included well intentioned slings and arrows, not to mention malicious insults and smears.

It might be worth mentioning a few of these animadversions. At the bar of a local tavern, General Conway called Washington "an old woman." Congressman Abraham Clark of New Jersey said: "We may talk of the enemy's cruelty as we will. But we have no greater cruelty to complain of than the management of our army." Congressman James Lovell of Massachusetts wrote to Samuel Adams that he had "little to say about our grand army." 'Tis a subject very sickening to even a strong stomach."

Washington's abusers assumed he would consider it beneath his dignity to answer these assaults. From the outset, he had been diffident about his ability to lead the army. Soon rather than later, they expected the humiliated general to resign his commission and go home to Mount Vernon. Instead, Washington stunned his opponents by fighting back.

The general applied to politics some crucial lessons he had already learned about fighting a war. He seized the initiative and threw his enemies on the defensive. He also utilized one of the favorite words in his military vocabulary: "Surprize." Best of all, when the hugger mugger ended, Washington forgave his vanquished foes and reenlisted them in the struggle for American liberty.

George Washington's political performance at Valley Forge is nothing less than a tour de force that adds a new dimension to his historical portrait. Among other things, I hope it will restore some respectability to that much misunderstood word, politician.