Schmitt was born as the son of a businessman in Plettenberg, Westphalia on July 11 1888; he studied state theory and law in Berlin, Munich and Straßburg and took his graduation and State promotion exams in Straßburg in 1915.
In 1921, Schmitt became a professor at the university of Greifswald, where he published his essay "Die Diktatur" ("The dictatorship"), in which he discussed the foundations of the Weimar Republic, emphasising the office of the Reichspräsident. This was followed by another essay in 1922, titled "Politische Theologie" ("political theology"); in it, Schmitt, who worked as a professor at the university of Bonn now, further substantiated his authoritarian theories, effectively denying free will based on a catholic world view. Another year later, Schmitt defended emerging totalitarian power structures in his paper "Die geistesgeschichtliche Lage des heutigen Parlamentarismus" (roughly: "The position of today's parliamentarianism in humanitarian history").
Schmitt changed universities again in 1926, when he became professor for law at the commercial college in Berlin, and in 1932, when we accepted a position in Cologne. It was in Cologne, too, that he wrote another paper, "Der Begriff des Politischen" ("The notion of the political"), in which he developed his controversial state law theories. Schmitt's theories in this paper were later used by the Nazis for an ideological foundation of their dictatorship, and Schmitt was later accused of having justified the "Führer" state with regard to legal philosphy.
In fact, Schmitt, who became a professor at the university of Berlin in 1933 (a position he remained in until the end of World War II) joined the NSDAP on May 1 1933; he quickly was appointed "preußischer Staatsrat" by Hermann Göring and became the president of the "Vereinigung nationalsozialistischer Juristen" ("Union of national-socialist jurisprudents") in November.
Half a year later, in June 1934, Schmitt became editor in chief for the professional newspaper "Deutsche Juristen-Zeitung" ("German jurisprudents' newspaper"); in July 1934, he justified the political murders of the Night of the Long Knives as the "highest form of administrative justice" ("höchste Form administrativer Justiz").
Schmitt presented himself as a radical anti-semite and also was the chairman of a law teachers' convention in Berlin in October 1936, where he demanded that German law be cleansed from the "jewish spirit" ("jüdischem Geist"); nevertheless, two months later, in December, the SS publication "Das schwarze Korps" accused Schmitt of being an opportunist and called his anti-semitism a mere mock-up, citing earlier statements in which he criticised the Nazi's racial theories. After this, Schmitt soon lost all of his prominent offices, and retreated from his position as a leading Nazi jurisprudent, although he remained as a professor in Berlin.
In 1945, Schmitt was captured by the American forces; after spending more than a year in an internment camp, he returned to his home town of Plettenberg following his release in 1946. Despite being isolated in the scientific and political community, he continued to study international law from the 1950s on.