He died at his Connecticut home from complications of a recent stroke, reports The New York Times. Sendak's friend (and onetime collaborator), playwright Tony Kushner, had been with him the past couple days, the rep tells PEOPLE.
Only last January, a frail but erudite Sendak made a memorable appearance on The Colbert Report, and said, "There's something in this country that is so opposed to understanding the complexity of children."
That is something Sendak, something of a big naughty kid himself, could never be accused of. For nearly 50 years, since the 1963 publication of his Where The Wild Things Are, Sendak has been a vital part of children's imaginations.
'Always Spoke the Truth'In a 1988 PEOPLE interview, Sendak defended his lifelong view that kids are tough enough for the grimmest fairy tales. "Parents shouldn't assume children are made out of sugar candy and will break and collapse instantly. Kids don't. We do."
"He always spoke the truth to children," Lisa Holton, his longtime publisher and friend, told PEOPLE on Tuesday. "It was always about the unvarnished truth about human life, which is why children loved him so much."
"Maurice was unique; he changed the landscape of what was possible in children's picture books," said veteran designer David Saylor. "And as a friend, he was delightfully funny and bawdy, sharply intelligent, and authentic."
Born in Brooklyn to a Garment District worker father, "Murray" Sendak was a frail, often bedridden child who delighted in drawing to escape his own many demons. Described by The New York Times as "lower class, Jewish, gay," Sendak told the paper in 2008, "All I wanted was to be straight so my parents could be happy. They never, never, never knew."
An early job was doing window displays at the iconic F.A.O. Schwarz toy store on Manhattan's Fifth Avenue, which led to an introduction to the children’s books editor at Harper & Row. Sendak's first illustration for a book was 1951's The Wonderful Farm, and the first he wrote and illustrated himself was 1956's Kenny’s Window, about a lonely little boy.
Among his several awards were the 1964 Caldecott Medal for Where the Wild Things Are, a 1970 Hans Christian Andersen Award for children's book illustration, and a 1982 National Book Award in the category of Picture Books for Outside Over There. Besides more than 50 books bearing his name, he also designed sets for operas, ballets, TV shows and stage productions.
The Times reports that his companion of 50 years, Eugene Glynn, a psychiatrist who specialized in the treatment of young people, died in 2007, and there were no other immediate family survivors.
With additional reporting by CHARLOTTE TRIGGS
Inset; David Corio / Michael Ochs Archive / Getty