In the pantheon of Greek politicians feted as much for fortitude as tenacity, few have stood out more than Manolis Glezos.

Tributes poured in Monday as word spread that the indefatigable Greek leftist, who as a teenager tore down the Nazi swastika flag from the Acropolis and more than seven decades later was elected as an MEP for the radical Syriza party, had died of heart failure at the age of 97.

“For all eternity he will remain the symbol of a fighter,” Alexis Tsipras, the party leader and former prime minister, said. “The left, all of us today, feel like orphans but also so lucky to have walked with him.”

Sentenced to death multiple times, confined to a prison cell for sixteen years and awarded the Lenin peace prize, Glezos took as much pride in his writing and political activism as he did his heroic wartime antics.

When, at the age of 92, he was elected to the European parliament, his enduring popularity saw him win more votes than any other Greek MEP, but it was his courage as a young man ripping down the swastika from the Acropolis, within days of Nazi forces overrunning Greece, for which he is most famous.

Then 18, the young Glezos had scaled the walls of the ancient citadel with a comrade in the dead of night on 30 May 1941 on a mission to remove the hated symbol. The first act of defiance under German occupation was credited with boosting morale and spurring the country’s resistance movement.

Glezos was subsequently arrested and tortured.

Manolis Glezos (left) spent time in prison during the Nazi occupation during the Second World War and during the Greek military dictatorship. Photograph: Geert Vanden Wijngaert/AP

Nikos Dendias, foreign minister in Greece’s current centre-right government, hailed Glezos “as a major figure of the national resistance against Nazi occupation. His stance inspired us all, irrespective of ideologies and parties,” he said.

Ordering that flags be lowered in his honour, the country’s prime minister, Kyriakos Mitsotakis, praised the resistance hero as a “symbol of our nation’s freedom”.

“[He] represented a generation that never gave way and never surrendered. That was never held prisoner to political fanaticism,” he said, adding he would always be remembered as a “lionhearted man with a tender gaze”.

“His death leaves Greeks poorer but the country richer for the life that he led and the example he gave: a genuine patriot and true fighter.”

Glezos’ interest in Greece’s war years never waned and he was considered the greatest living authority on the resistance movement against Hitler’s occupying forces, penning two voluminous tomes, both running to more than 800 page, on the period. Years in prison – after being arrested and tried for his political convictions, first during the 1946-49 Greek civil war and, then, the 1967-74 military dictatorship - were spent reading.

“When I wasn’t doing that I would write on the back of cigarette and match boxes,” he once told the Guardian. “Or try to talk to the guards.”

Determined to keep the issue of Hitler’s war crimes alive, he vociferously campaigned well into his 90s for German reparations as compensation for the atrocities Greeks suffered at the hands of the Nazis.

At the height of the debt-stricken country’s economic crisis, when Athens was often pitted against Berlin, Glezos again emerged as a symbol of resistance. He was often to be seen, tousled white hair under seaman’s cap, his frame steadied by a walking cane, participating in mass anti-austerity protests and in one now notorious incident was carried away by fellow demonstrators after being tear gassed in the face at the foot of the Greek parliament.

Throughout Athens’ battle to keep afloat and inside the eurozone, he remained a sworn enemy of the fiscal measures he believed were eviscerating poorer sections of society.

“Greece is the guinea pig of policies exacted by governments whose only God is money,” he said, vowing to give voice to the people most affected by them.

A man of immense rigour and regimen, Glezos, who lived with his wife Georgia in a little house in Athens filled with books, was a great believer in the afternoon nap – a legacy of exile and imprisonment. “That way I get two days out of one,” he confided. “I start at 7am, stop at 3pm, start again at 5pm and go all the way through to midnight. I get a tremendous amount done.”