[4] On 16 January 1920 Ottmar Bühler was appointed to an extraordinary professorship in public law at the University of Münster.
However, during 1933 Germany became a one-party dictatorship and it is hard to see how he could have pursued his academic career effectively during the twelve Nazi years without being broadly supportive of the political establishment of the time.
[4] In 1942 he accepted an invitation to transfer to the University of Cologne where he was installed in Germany's first teaching chair dedicated to international finance and tax law.
[4] The end of the war in May 1945 was accompanied by a collapse of the Hitler government, and what remained of Germany was divided into four military occupation zones.
For him the task of bringing the tax regime back inline with legal principals was all the more urgent under allied military occupation because of the extent to which the Hitler régime had largely ignored such niceties ("beim Vollzug dieser Gesetze die rechtsstaatlichen Postulate, die der Hitlerstaat so weitgehend mißachtet hatte, wieder zur Geltung zu bringen").
This meant that Cologne, which for decades had been one of the country's largest universities, now became the national centre for academic research and teaching on tax law.
[1] After the combined relaunch of the US, UK and French occupation zones as the German Federal Republic (West Germany) in May 1949, Otto Bühler was involved in taxation reform through his membership of the Academic Advisory Board at the new country's Finance Ministry.
He now took the opportunity to update comprehensively his two volume core work, "Steuerrecht" ("Tax Law") which filled a gaping hole in the postwar market for academic text books.
[4] Munich University still awards an annual Ottmar Bühler Prize for outstanding academic achievements in the field of business taxation teaching and research.