Renowned illustrator and artist Leo Dillon died on May 26 from “complications of a sudden illness requiring lung surgery,” according to Bonnie Verburg, his longtime editor at Scholastic's Blue Sky Press imprint, and formerly Harcourt. Dillon was 79. With his wife and collaborator Diane, he illustrated over 40 children’s books spanning a career of more than 50 years. As a duo, the Dillons won numerous prestigious awards, including back-to-back Caldecott Medals in 1976 and 1977 for Why Mosquitoes Buzz in People’s Ears by Verna Aardema and Ashanti to Zulu: African Traditions by Margaret Musgrove, respectively.

Dillon was born in Brooklyn, N.Y. in 1933 and grew up there as well. As a young man he pursued his dreams of being an artist by attending Parsons School of Design in New York City. It was there that he met Diane Sorber, originally from Glendale, Calif., in 1953. The two students were said to be competitive though they always admired each other’s talents. The pair married in 1957, and shortly thereafter began work as freelance artists in a shared studio where they critiqued and added to each other’s projects. As they blossomed into a seamless illustrating team, they have said in interviews that it was impossible to tell who contributed which elements to any particular piece. They have been widely praised for an elegant and sophisticated style that incorporated multicultural elements. “We are interracial and we decided early in our career that we wanted to represent all races and to show people that were rarely seen in children’s books at that time,” Diane Dillon told a group of Scholastic students in 2003.

The first picture book they illustrated was The Ring in the Prairie, a Native American tale by John Bierhorst (Dial Press, 1970, and the first chapter book was Hakon of Rogen’s Saga by Eric Hagard (Houghton, 1963). In 2002, they published the first picture book they wrote themselves, Rap a Tap Tap: Here’s Bojangles—Think of That! (Scholastic/Blue Sky). Their many beloved titles also include The People Could Fly: American Black Folktales, written by Virginia Hamilton (Knopf, 1985) and To Everything There Is a Season (Scholastic, 1998). Among their other accolades are a Coretta Scott King Award and five Coretta Scott King Honors, as well as five New York Times Best Illustrated Awards.

In addition to their work in children’s books, the Dillons had an established fan base for their cover designs for adult science fiction books, most notably many titles by Harlan Ellison and others for the original Ace Specials series of sci-fi and fantasy titles.

At the time of Leo’s death the Dillons were completing work for If Kids Ran the World, a book that fancifully envisions children helping other children to solve such world issues as feeding those in need and providing shelter for the homeless. The book will be published by Scholastic/Blue Sky Press in 2014, and proceeds will be donated to various charities.

Dillon is survived by Diane Dillon and their son Lee, also an artist.