I.K. Bonset said to be the same as Theo van Doesburg
Early life
Theo van Doesburg was born Christian Emil Marie Küpper on 30 August 1883, in Utrecht, Netherlands, as the son of the photographer Wilhelm Küpper and Henrietta Catherina Margadant. After a short period of training in acting and singing, he decided to become a storekeeper. He always regarded his stepfather, Theodorus Doesburg, to be his natural father, so that his first works are signed with Theo Doesburg, to which he later added "van".