Career
In 1928, he started his chess career in Nuremberg, playing at Arbeiterschachklub Nürnberg, then Nürnberger Schachklub Noris. In 1933, he was arrested by Nazis, and spent two years in a Nuremberg prison and three years in the Dachau concentration camp, until 1939. After his releasing, he worked in a factory (Faber-Castell bzw Schwan-Bleistift), and again played chess in Nuremberg (Schachklub Noris).
In October 1942, he was drafted into the Wehrmacht, and sent to the Eastern Front in March 1943.
He fought in the Kharkov region and in the Battle of Kursk in July 1943. He was injured in combat, and awarded the Iron Cross, 2nd Class.
Then, he spent several weeks in a field hospital in Bad Blankenburg, Thuringia. In March 1945 he was in the Western Front, and after Western Allied invasion of Germany, he had been taken into Allied captivity.
From April to September 1945, he was kept in an American army camp (Lager 2227) in Ostend, Belgium.
After his release on September 2, 1945, he returned to Nuremberg, and next to Bad Blankenburg, then the Soviet occupation zone. He received a doctorate of pedagogy (1948), and a habilitation in philosophy (1950) from the University of Jena, Thuringia. In 1953, he played in a friendly match German Democratic Republic versus
Bulgaria in Sofia, and was the Präsident der Sektion Schach der Deutsche Demokratische Republik in 1953/54.
From 1953, he worked at the Humboldt University of Berlin, and from 1959 in the Academy of Sciences of the German Democratic Republic. Klaus published in 1963 a collection of papers on "Cybernetics in Science, Technology, and Economics in the German Democratic Republic." After fighting a running battle with bureaucracy in the journals from 1963 on, Klaus was asked to prepare a "Cybernetic Dictionary" as his contribution to the Seventh Congress of the SED in 1967.