Oswald Pohl (1892-1951) rose to high Nazi rank principally through financial and administrative management skill, eventually heading the Schutzstaffel's (SS) economic administration, its Economic and Administrative Main Office (WVHA), whose responsibilities included the actual operation of the concentration camp system. A protege of Heinrich Himmler, he was identified with the part of Holocaust that wanted maximum economic exploitation of the Jews, as opposed to the security side that wanted them destroyed as soon as possible.
His immediate deputies in the WVHA were August Frank and Georg Loerner. There were five office groups, WVHA Amtsgruppe A-D, each with a chief, and WVHA Amtsgruppe W, "SS businesses", which he directed personally. Tried in the Pohl Case of the Nuremberg Military Tribunals, he was executed by hanging.
Pohl converted to Catholicism before his execution, and published his confession.  His confessor, the prison chaplain, Karl Morgenschweis, helped him write it, commenting "“As priest and pastoral counselor, I have the holy duty to portray Pohl in just the way as I have seen him as his spiritual father and soul-guide in the several years of direct intercourse [Verkehr] with him." Morgenschweis does not excuse his offenses, but gives some insight into the man.
What motivated him? Some have seen him largely as a technocrat. Allen, however, sees him as driven by a "plexus of ideologies", following Heinrich Himmler's dual goal of producing the SS-State and making it efficient.  He rejects Hannah Arendt's idea of a mindless Adolf Eichmann expressing the "banality of evil," although takes her biography as a point of departure. 
He joined the German Navy in 1912, served in World War I, and then became a paymaster in 1918. After the war, he took trade school and university course, but dropped out and "became paymaster for the Freikorps "Brigade Löwenfeld", working in Berlin, Upper Silesia and the Ruhr basin, rejoining the Navy in 1920.
Becoming a Nazi
First joining the SA in 1925, he joined the Nazi Party in 1926. "He met Heinrich Himmler in 1933 and became his protége. He was appointed chief of the administration department in the staff of the Reichsführer-SS ("Reich leader SS", RFSS) and given the rank of SS-Standartenführer on February 1, 1934, and began to influence the administration of the concentration camps."
- Bjorn Krondorfer (June 2008), "A Perpetrator’s Confession: Gender and Religion in Oswald Pohl’s Conversion Narrative", Journal of Men, Masculinities and Spirituality 2 (2)
- L. M. Stallbaumer-Beishline (July 2003), The Ideology of SS Bureaucrats: book review of Michael Thad Allen. The Business of Genocide: The SS, Slave Labor, and the Concentration Camps., H-Net
- Michael Thad Allen, Introduction, The Business of Genocide: The SS, Slave Labor, and the Concentration Camps, University of North Carolina Press
- Oswald Pohl, Jewish Virtual Library