Horst Janssen was born on 14 November 1929 as an illegitimate child in Wandsbek, near Hamburg, and grew up in Oldenburg with his grandparents. His great talent as a draughtsman became apparent whilst he was still at school. After the end of the Second World War and the death of his mother and grandparents, his aunt took the 15-year-old Janssen to live with her in Hamburg. She supported his education at the Landeskunstschule, where he became a master student under Alfred Mahlau.

A successful artistic career began, one that would bring the artist worldwide fame for his drawings and his prints. His exhibitions were held in New York, Chicago, Los Angeles, Tokyo, Taipei, Moscow, Venice, Rome, Oslo, Paris, Hamburg, Dresden, Oldenburg and many other cities.

Janssen’s life story, which from birth was marked by separation and loss, led to alcohol abuse and interpersonal crises, in which violence certainly played a part.

In later life, Janssen increasingly recalled his happy childhood in Oldenburg. In 1992, he was awarded honorary citizenship of the city of Oldenburg. Horst Janssen died on 31 August 1995 and, in accordance with his own wishes, was buried at St Gertruden Cemetery in Oldenburg.