Lloyd Alexander, 83, one of the best-known authors of fantasy, adventure and coming-of-age novels of the last several decades, died of cancer Thursday at home in Drexel Hill.

Mr. Alexander wrote more than 40 books, and was compared to such writers of fantasy literature as J.R.R. Tolkien.

Mr. Alexander won a 1971 National Book Award for The Marvelous Misadventures of Sebastian, about a princess saved by a fiddler in the 19th century; a 1982 American Book Award for Westmark, the debut novel in a trilogy of a printer's apprentice caught up in political intrigue; a 1969 Newbery Medal for the fifth and final book in his Chronicles of Prydain series, inspired by Welsh mythology; several Parents Choice Award winners; the Pennbook Lifetime Achievement Award by the Free Library of Philadelphia in 1991; and several international awards.

The first two books of The Chronicles of Prydain were adapted into the Disney animated feature The Black Cauldron, released in 1985.

Mr. Alexander's fantasies, written for children and adolescents, also appeal to adults. They explore complex questions: What's the point of war? How can you be a good person in inhumane situations? What is courage?

He created fantasy characters who found hope as they struggled with life's problems by using cats that fly and violins that play at will.

"Life is a tough piece of business," he said in a 1992 Inquirer article. "I don't buy the idea that if you work hard enough, you'll eventually win out. You'll probably get your head busted. The only thing I will say is that if you give up hope, you're lost. My books are that message to myself."

Mr. Alexander was born in Center City, the son of stockbroker who, after the crash of 1929, devised money-making schemes to make ends meet.

When the imaginative boy discovered Dickens, he said, "Now, this is my family." He also was fascinated with Greek and Celtic mythology.

His family moved to Drexel Hill, and Mr. Alexander graduated from Upper Darby High School at 16. He yearned to be a writer.

Mr. Alexander worked for a while as a bank messenger, a job he disliked. He wrote about his experiences in his first published adult novel, And Let the Credit Go (1955).

At 19, Mr. Alexander was looking for adventure. The country had entered World War II, and he joined the Army.

Eventually, Mr. Alexander served in a counterintelligence unit, interrogating prisoners and translating. On VE day, he was stationed in Paris, where he met his future wife, Janine Denni, and her young daughter.

After his discharge in 1946, Mr. Alexander attended the Sorbonne and met Gertrude Stein and surrealist poet Paul Eluard.

"He was one of the shiest people in the world. Still, he was enormously talented," Edwin Johnson-Muller, a friend in Philadelphia, said in 1992. "Almost anything - music, languages - he picked up so fast."

Mr. Alexander brought his bride and stepdaughter to the United States in 1947 and settled in Drexel Hill, where he worked odd jobs by day and tried to write a semiautobiographical war novel by night. It was a resounding flop.

Publisher's rejections piled up for seven years, and Mr. Alexander fell into despair. "I took a humble view at myself," he said in 1992. "It was like, 'OK, am I going to live?' "

During the war, Mr. Alexander had became enraptured by the rough-hewn country of Wales, which worked its way into his children's fantasies, the first of which was Time Cat: The Remarkable Journeys of Jason and Gareth (1963).

He began to combine the stories of King Arthur with his memories, creating the mythological world that would be the setting for The Chronicles of Prydain, which many critics recommend for readers enthralled by the Harry Potter series.

In the early 1970s, Mr. Alexander's contributions helped launch Cricket, a literary magazine for children.

"He is one of the truly great authors of children's literature," said Mike Tunnell, who published a guide for The Chronicles of Prydain.

Mr. Alexander's last book in a career that lasted a half-century was The Golden Dream of Carlo Chuchio, which will be published in August.

Mr. Alexander's wife died May 2. His stepdaughter, Madeline Khalil, died in 1990. He is survived by five grandchildren and five great-grandchildren.

Services are private.

To read more about Lloyd Alexander and listen to clips from some of his books, go to http://go.philly.com/alexander