Künstler, whose father was a barber, worked at a post office in Kassel in 1915, against the wishes of his parents, after completing school.
From 1919, he was a Berufssoldat (professional soldier) and served for 12 years in the Reichswehr, where he attended the Heeresfachschule für Verwaltung und Wirtschaft (Army Technical School of Management and Economics) in addition to various training courses.
After a completed course at the SS-Junkerschule Bad Tölz in 1936, he was transferred to the SS-Totenkopfstandarte Oberbayern and rose to become its commander in December 1939.
He was succeeded for two months by his deputy, Schutzhaftlagerführer Karl Fritzsch, before Egon Zill was appointed camp commandant.
After that, he was demoted to the 7th SS Volunteer Mountain Division Prinz Eugen and probably died in the Battle of Nuremberg in April 1945.