Tomi Ungerer (1931 — 2019) began his unstoppable career as an illustrator, childrenʼs book author and artist in New York. He published more than 140 books for adults and children, and created posters, sculptures and films. His hometown, Strasbourg, dedicated a museum to him even during his lifetime. His picture books, such as The Three Robbers and Moon Man, are modern classics.

Johanna Spyri (1827-1901) was born Johanna Heusser, the daughter of the village doctor in Hirzel, just south of Zurich. In 1852 she married the young lawyer Johann Bernhard Spyri and moved to Zurich. Her first story A Leaf on Vrony's Grave appeared anonymously in 1871, when she was already 43. Encouraged by its success, she followed it up with several more tales, but it was only in 1878 that her first book for children appeared. The first Heidi novel - Heidi's Years of Learning and Travel - came out in 1880. It was only in response to popular demand that she wrote the follow-up - Heidi Makes Use of What She Has Learned - which was published the following year. The two together make up the novel now known simply as Heidi.