It was included in his photography landmark book Antlitz der Zeit (1929), and became one of the most famous pictures that Sander took back then.
[1] The picture depicts four young men seated, who are, from left to right, Erich Sander, the photographers son, and a philosophy student, and three of his friends, Richard Kreutzberg, Hans Schoemann, and Georg Hansen, all politically involved as members of the Communist Party of Germany.
Sander was imprisoned by the Nazi regimen in 1934 and died ten years later, still in custody, Kreutzberg took his own life in 1933, the same year the Nazis seized power, Schoemann would be a member of the German resistance during World War II, and Hansen was arrested in London, in 1932, on charges of espionage for the Soviet Union.
Their closeness and committed expressions seems to reflect their common political and social ideology, goals and purposes.
[3] A print of the photograph was sold by $493,000 at Sotheby's New York, on 7 April 2008, making it then the highest price for one of the artist works.