Harald Szeemann was a key figure of the European and international artistic avant-garde from the 1960s onwards. Szeemann was the first curator to mount large surveys of the fertile breakdown of art mediums that began in the 1960s, and the first to have complete control over the sprawling documenta exhibitions, which are held every five years or so in Kassel, Germany. He was known for shows that not only mixed genres and generations, but sometimes included historical documents and scientific innovations.
From 1981 to 1991 Harald Szeemann was the sole curator of the Kunsthaus Zürich; he was director of the Kunsthalle Bern from 1961 to 1969. His best-known exhibitions include When Attitude Becomes Form: Live in Your Head (1969) and documenta V (1972). He initiated Aperto, a section showing young and rediscovered artists, at the 1980 Venice Biennale. He was among the few to curate the Biennale twice, in 1999 and 2001. He curated important retrospectives of Mario Merz and Joseph Beuys, among others, at the Kunsthaus Zurich, as well as exhibitions in Vienna, Dusseldorf, Berlin, Rotterdam, Hamburg, Tokyo, and Bordeaux.