How was Karl Landsteiner awarded the Noble Prize in Physiology or Medicine?

Name: Karl Landsteiner.
Country: Austria.
Date of Birth: 14 June 1868.
Died: 26 June 1943.
Education: University of Vienna.
Subjects Of Study: ABO blood group system blood group.
Known as: Research of blood group systems, the discovery of Rh factor, and the discovery of poliovirus.
Noble Prize Year: Nobel Prize for Peace in 1930, for his discovery of human blood groups.