"I have never met a boy who so persistently writes the exact opposite of what he means," a teacher once wrote in the young Roald Dahl's report card. "He seems incapable of marshaling his thoughts on paper." From such inauspicious beginnings emerged an immensely successful author whom The Evening Standard would one day dub "one of the greatest children's writers of all time."

Dahl may have been an unenthusiastic student, but he loved adventure stories, and when he finished school he went out into the world to have some adventures of his own. He went abroad as a representative of the Shell corporation in Dar-es-Salaam, and then served in World War II as a pilot in the Royal Air Force. After the war, Dahl began his writing career in earnest, publishing two well-received collections of short stories for adults, along with one flop of a novel.

The short stories, full of tension and subtle psychological horror, didn't seem to presage a children's author. Malcolm Bradbury wrote in The New York Times Book Review, "[Dahl's] characters are usually ignoble: he knows the dog beneath the skin, or works hard to find it." Yet this talent for finding, and exposing, the nastier sides of grown-up behavior served him well in writing for children. As Dahl put it, "Writing is all propaganda, in a sense. You can get at greediness and selfishness by making them look ridiculous. The greatest attribute of a human being is kindness, and all the other qualities like bravery and perseverance are secondary to that."

In 1953, Dahl married the actress Patricia Neal; two of his early children's books, James and the Giant Peach (1961) and Charlie and the Chocolate Factory (1964) grew out of the bedtime stories he made up for their children. Elaine Moss, writing in the Times, called the latter "the funniest children's book I have read in years; not just funny but shot through with a zany pathos which touches the young heart." Charlie and the Chocolate Factory was a colossal hit. A film version starring Gene Wilder was released in 1971 (as Willy Wonka and the Chocolate Factory), while James and the Giant Peach was made into a movie in 1996.

Dahl followed his initial successes with a string of bestsellers, including Danny, the Champion of the World, The Twits, The BFG, The Witches and Matilda. Some adults objected to the books' violence -- unpleasant characters (like James¿s Aunts Sponge and Spiker) tend to get bumped off in grotesque and inventive ways -- but Dahl defended his stories as part of a tradition of gruesome fairy tales in which mean people get what they deserve. "These tales are pretty rough, but the violence is confined to a magical time and place," he said, adding that children like violent stories as long as they're "tied to fantasy and humor." By the time of his death in 1990, Dahl's mischievous wit had captivated so many readers that The Times called him "one of the most widely read and influential writers of our generation."