ATHENS, Greece (AP) — Former Greek President Christos Sartzetakis, a judge widely respected for resisting pressure from military dictators who ultimately imprisoned him without trial in the late 1960s, has died following a long hospitalization. He was 92.

Sartzetakis had been hospitalized in the intensive care unit of Athens’ Laiko hospital and died in the early hours of Thursday of respiratory failure, the hospital said in a statement.

Born in April 1929, Sartzetakis held the largely ceremonial post of president of Greece from 1985-1990, a politically tumultuous time in the country.

“During the 1989-90 period, in an atmosphere of intense political tension, his work on the formation of a government was impeccable,” said Prime Minister Kyriakos Mitsotakis, extending his condolences to Sartzetakis’ family.

Sartzetakis first rose to prominence over his role as an investigating judge in the 1963 murder of politician Grigoris Lambrakis by right-wing extremists, and was lauded for resisting intense political pressure during the case. Lambrakis’ killing triggered mass protests and a political crisis.

“During difficult times for the country and for democracy, (Sartzetakis) handled the case of the Lambrakis murder as an investigating judge with exemplary independence and judicial ethos, paying a heavy price for this stance during the years of the junta,” said current President Katerina Sakellaropoulou in a statement. “Later, as President of the Republic, he honored the office with conscientiousness, dedication and a high sense of responsibility in the execution of his duties.”

Born in the northern Greek city of Thessaloniki, Sartzetakis studied law and joined the judiciary in 1955. He was fired from the judicial branch in 1968 during the military dictatorship, arrested, tortured and imprisoned without trial. He was eventually released in 1971 and was reinstated into the judiciary after the fall of the junta in 1974, rising to become a Supreme Court judge in 1982. He was nominated as president by the socialist PASOK party in 1985, and served in that position until May 1990.

Sartzetakis is survived by his wife and their daughter.