Better known as GAN, Adrian-Nilsson was born in a working-class area of the Swedish university town of Lund. In his early poems and paintings he was evidently influenced by Oscar Wilde and Aubrey Beardsley. He soon came to discover Cubism and Futurism and painted his first modernistic work in 1913.
After spending time in Berlin and Köln, he returned to Lund in 1914. During GAN's absence, his lover Karl Edvard Holmstöm had died of pneumonia, a loss from which GAN never recovered.
Adrian-Nilsson introduced Surrealism to his country. After moving to Stockholm, GAN focused on painting sailors, that he had also as lovers and friends. One of them, Edvin Andresson, who later changed his name to Ganborg, was to become a lifelong friend and promoter of GAN's work.
In 1984 a grand retrospective exhibition made GAN celebrated and recognized as an unique painter who had created numerous modernistic syntheses in which his gay identity was by far a more important element than any purely artistic influence.