Although known for his lively mind and wit, he could read turgid and mind-numbing speeches extolling the virtues of a state he must have found it hard at times to like.
For the last decade of his working life he was chairman of the State Secretariat for Church Affairs, the body supposed to liaise with religious groups but which acted - in parallel with the secret police, the Stasi - to control them. Summoned out of the blue by Erich Honecker in November 1979 to be informed of the appointment, Gysi was told by the party leader, "Remember, you will report only to me!"
Although religious groups in the GDR had a latitude almost unparalleled in Communist-ruled Europe, they were required to adopt an attitude of public loyalty to the state. The Lutheran Churches dubbed this "critical solidarity". Gysi extolled this model, playing down in public his unhappiness at the rebellious spirit lurking below the surface. "The attempt at co-operation between Church and State is a historic experiment," he declared in 1981. Gysi saw his main task as to keep the Lutheran Churches - the largest in East Germany - on the straight and narrow, and to prevent them from sheltering enemies of the system.
Despite his commitment to Communism, Gysi had a bourgeois background as the son of a Berlin doctor and his Jewish wife. He attended grammar school in the city, while becoming increasingly involved in Communist activity. He was enrolled by his mother in the Communist Youth Union when he was 16, becoming a member of the German Communist Party (KPD) three years later. He studied economics in Frankfurt, Paris and Berlin, where he was active with the Red Students' Movement.
With the growing persecution of the Jews by the Hitler regime, Gysi's parents divorced and his mother fled to France. Klaus and his fiancee, the Russian-born Irene Lessing (they had met while at university in Berlin, but Nazi racial laws made marriage impossible), visited her in 1939 - she pleaded with them not to return to Germany. They resolved to go back but the German invasion intervened and the young couple were briefly interned in Toulouse before escaping.
Despite the dangers - Gysi was doubly under threat as a Jew and as a Communist - they moved back to Nazi Germany in 1940 (the party believed he would not be arrested as he did not "look Jewish"). He worked underground throughout the rest of the Nazi regime from a base in his fiancee's mansion on Berlin's Schlachtensee. It was only after the end of the war that he could at last marry Irene (sister-in-law of the novelist Doris Lessing).
Once the Soviets had invaded the Eastern part of Germany, Gysi threw himself into building a socialist country, joining the SED when it was established. He was appointed by the Soviets as mayor of the Berlin district of Zehlendorf in 1945 (though he continued to live in the American sector) and deputy head of the Culture League, set up to rebuild a Communist cultural identity. Gysi welcomed back to the Soviet zone of Germany such writers as Bertolt Brecht, Stefan Heym and Anna Seghers.
He became chief editor of the political and cultural journal Aufbau, before becoming a member of the GDR parliament, the Volkskammer, where he was chairman of the Education committee. He joined a publishing house in 1952 (while still a member of parliament).
In 1953 - as Communist anti-Semitism spread from Moscow across Eastern Europe - Gysi was removed from his official posts, but after six months the spasm had passed and his career resumed. In 1957 he was appointed head of the Aufbau publishing house in East Berlin, which he had helped found in 1945. He replaced the previous incumbent Walther Janka, who had been arrested - some said after Gysi had denounced him to the Stasi. Although Gysi denied this allegation, it is known that from then on he had regular contacts with the Stasi, and was assigned the codename "Kurt".
In January 1966 he was appointed minister of culture, holding the post until he fell victim in 1972 to the purges of the new party leader Erich Honecker. During his period as cultural overseer he broadened the range of what was tolerated in literature and the arts, but continued to espouse in public the party line. He was appointed as GDR ambassador to Italy in 1973, remaining in Rome until August 1978.
By the mid-1980s, Gysi had privately recognised that the GDR was doomed. As anti-government dem-onstrations broke out in early 1988, with support from some sections of the Lutheran Church, his star began to fall among the party leadership. He was finally sacked in July that year as the Communist system was beginning to unravel. His request to be allowed to organise the 50th anniversary commemoration of the Kristallnacht attacks on Jewish homes and synagogues was rejected.
Gysi lived to see the Communist Germany he had fought and worked for disintegrate and be swallowed by the capitalist Germany. He lived the rest of his life in seclusion. It fell to his son Gregor, the head of the Party of Democratic Socialists (as the SED became), to salvage what he considered worth saving from the wreckage of GDR politics.
Although he served the Communist regime faithfully through all its twists and turns, Gysi was never quite trusted by the party nomenklatura. His experience of life outside Germany, compounded by his Jewish origins, cast a shadow over his loyalties and he never made it into the Politburo. On the other side, his Stasi contacts and willingness to toe the party line made him an object of suspicion. Even his son denounced his "foul compromises".
A colleague once said he was "a devil at the front, an angel at the back". Few will ever know what Klaus Gysi really believed.
Klaus Gysi, politician: born Berlin 3 March 1912; GDR culture minister 1966-73; GDR ambassador to Italy 1973-79; State Secretary for Church Affairs 1979-88; twice married (one son, one daughter); died Berlin 6 March 1999.