Mihajlo Mihajlov, a prominent dissident in the former Yugoslavia who later taught at Yale, died in Belgrade on Sunday, Agence France-Presse reports. He was 76.

Mihajlov was a professor of Russian literature at the University of Zagreb in the early 1960s before he was imprisoned by the Communist government of Josip Broz Tito for writing an essay about dissidents’ camps in the 1917 Russian revolution. He was sentenced again in 1975 for disseminating propaganda.

He was released in 1978 and allowed to leave the country. In the United States he taught Russian literature and philosophy courses at Yale, The Ohio State University and the University of Virginia.