Jansson published her first Moomin book, introducing the Moomin characters to the world for the first time.
In 1945, Tove Jansson published Småtrollen och den stora översvämningen ("The Moomins and the Great Flood"), the first book to feature the Moomin characters who would come to define her legacy. Written during the difficult years of the Second World War as an escape from the grim realities of conflict, the book introduced Moominvalley and its gentle, round, troll-like inhabitants to readers for the first time.
The book received little immediate attention, but it planted the seed for what would become a globally beloved franchise spanning novels, comic strips, picture books, television series, and merchandise. The Moomins' whimsical yet philosophically rich world — dealing with themes of tolerance, family, environmentalism, and existential anxiety beneath a charming surface — resonated deeply with both children and adults, an unusual duality for the genre at the time.
This debut marked the beginning of a literary phenomenon that would eventually be translated into over 50 languages and make Jansson one of Finland's most internationally recognized cultural exports. It also represented a significant, if initially modest, first step for a woman working in the male-dominated postwar publishing industry, establishing her as an author-illustrator entirely in command of both text and image — a rare and demanding combination.