In 1932-1934 he was influenced by Marxist ideologies and joined the Communist Party of Greece.
[2] Hatzis got involved in the Greek Civil War (1946-1949), where he joined the Democratic Army of Greece (DSE).
As a result, following the Left's defeat, he went into exile and until the legalization of the Greek Communist Party in 1975, he lived in various socialist countries in Eastern Europe.
[3] In 1962 Hatzis took up a position at the Byzantine Studies Department at the University of Budapest.
He also worked on the translation and anthology of a wealth of texts in the Hungarian language.