Kay Nielsen was a Danish illustrator and artist, born on March 12, 1886, in Copenhagen. He is best known for his enchanting illustrations in fairy tale books, particularly those of Hans Christian Andersen and Grimm Brothers. His unique style combines elements of Art Nouveau and the early 20th-century aesthetic, characterized by intricate line work and vibrant colors. Nielsen's work gained significant recognition in the 1920s, especially with his illustrations for the book East of the Sun and West of the Moon. His artistic contributions have left a lasting impact on the world of children's literature and continue to inspire artists and illustrators today.