Education
After serving in the military for the required time Posser studied law and became a lawyer in 1951.
After serving in the military for the required time Posser studied law and became a lawyer in 1951.
In 1952 he founded, with the former Secretary of the Interior Gustav Heinemann (previously of the Christian Democratic Union), Hans Bodensteiner (from the Christlich Soziale Union (Christian Social Union)), Thea Arnold, Helene Wessel (both from the Zentrumspartei), Hermann Etzel (Bayernpartei), and the future President Johannes Rau the pacifist All-German People"s Party, of which he was made General Secretary after the 1953 resignation of Bodensteiner. In 1968 he was named the Minister for Federal Affairs. In 1972 he switched to the Judicial Department, before he became Finance Minister in 1978.
He held this position until 1988 in the second and third cabinets of President Rau.
He was also an advisor to the Premier. Posser was the Godfather of actor Diether Krebs.
Social Democratic Party of Germany, All-German People"s Party.
After the party"s collapse in 1957, he became a member of the Social Democratic Party of Germany, for whom he joined the Landtag of North Rhine-Westphalia in 1966.