After World War II, he became a prominent politician in East Germany's Socialist Unity Party (SED) and was one of its longest-serving members until German reunification.

His father was Hermann Gysi (1888–1950) , a local doctor whose family originated from Switzerland, and his mother was Erna Potolowsky (1893–1966), a bookkeeper of Jewish descent from Weilburg.

[1][2] He attended grade school and Realgymnasium in Neukölln and in 1928, joined the Young Communist League of Germany, the Workers International Relief and the Sozialistischer Schülerbund.

The same year, Gysi was sent to Germany in order to conduct covert operations for the KPD, under party functionary Jens König.

During this time, Gysi's maternal uncle and aunt were killed in Auschwitz concentration camp in 1943.

From 1973 to 1978, Gysi was ambassador to Italy, and a diplomat in Vatican City [dubious – discuss] and Malta.

In November 1979 Gysi succeeded Hans Seigewasser as the State Secretary for Church Affairs, remaining in this position until his retirement in 1988.