Ivar Arosenius was born with hereditary hemophilia, which affected his entire life. Doctors prescribed alcohol to keep his blood fluid, along with good food and long walks.

His studies were fragmented: the Valand School of Painting, the Royal Academy of Fine Arts in Stockholm, and the Artists’ Association School. None of them really suited him. Instead, he was shaped by travels to Munich and Paris, by the wild nature of Värmland, and by a deep interest in Italian Renaissance painting. From this, he created something entirely his own—a visual world that appears childlike on the surface but carries a sophisticated artistic heritage.

His breakthrough came in the autumn of 1908, with an exhibition at Valand. At the time, he was living in Älvängen with his wife Ida and their daughter Eva, known as Lillan, who appears in many of his works. It was a happy and productive period. He painted on the interior doors of the house and created his classic picture books, in which Lillan embarks on thrilling adventures.

On New Year’s Eve 1908–1909, he developed a mild throat infection; the next day it worsened, and that evening he suddenly collapsed. A blood vessel in his throat had ruptured, and due to his hemophilia, this led to his untimely death. Kattresan was published posthumously, and his definitive breakthrough came after his death. Ivar Arosenius was only thirty years old.