Nobel Prize-winning author Guenter Grass, who has died at the age of 87, was regarded as Germany's greatest post-war writer. But in 2006, his revelation that he had served in the Waffen SS during World War Two caused a sensation.
A novelist, poet and playwright who was not afraid to confront his country's wartime past, Guenter Grass was often cast as the "conscience of his generation".
He found fame with his first novel The Tin Drum, published in 1959, which gave a savagely comic picture of the rise and fall of Nazism through the eyes of a young boy named Oskar.
Awarding him the Nobel Prize for Literature in 1999, the Swedish Academy cited his courage in "recalling the disavowed and the forgotten: the victims, losers and lies that people wanted to forget because they had once believed in them".
But his moral authority was tarnished seven years later when he revealed that, at the end of the war, he had served in the Waffen SS, the elite fighting force that also ran the concentration camps.
Many Germans were shocked. Grass had earned his reputation on left-leaning statements urging his countrymen to come to terms with their Nazi past, yet he had spent 60 years hiding his.
The criticisms were summed up by his biographer Michael Jurgs, who said: "We adored him as a moral icon... In a way he has betrayed an entire generation."
Gunter Grass was born in 1927 in Danzig, now the Polish city of Gdansk.
Like many boys of his age, he became a member of the Hitler Youth. In the original version of his life story, he said he was a "flakhelfer" - a conscript forced to operate anti-aircraft guns.
In fact, he volunteered for submarine service at 15 but was turned down. Then, in 1944, at the age of 17, he was called up to the SS.
'Sense of shame'
At the time, he said he had not felt ashamed to be a member and never fired a shot.
But he later wrote: "What I had accepted with the stupid pride of youth I wanted to conceal after the war out of a recurrent sense of shame. But the burden remained, and no-one could alleviate it."
After the war, Grass worked as a potash miner and as assistant to a monumental mason, and later as a creative sculptor and poet.
But it was the Tin Drum that made his international reputation as a writer.
Its three-foot tall protagonist Oskar deliberately stopped himself from growing by throwing himself down the stairs at the age of three.
With Grass deploying provocative and irreverent wit and wordplay, Oskar comments - not always reliably - on the horrors, injustices, and eccentricities of the war and its aftermath in Germany.
It was in contrast to the sparse, sober literature of the 1950s, when many German authors felt they were writing in a language which had been "polluted" by the Nazis.
After The Tin Drum, Grass found further successes with books including Cat and Mouse and Dog Years, and with some of his plays.
He was also a vigorous political commentator, criticising both the Communist regime in East Germany and what he called "the narrow-chested radicals" of the student movement.
He lent his support to the Social Democrats, particularly to West German Chancellor Willy Brandt, on whose behalf he campaigned in the 1960s and '70s.
When the Berlin Wall fell in 1989, however, he ploughed a relatively lonely furrow. Grass called for a "confederation of two German states", warning that a reunified Germany would want to flex its muscles.
Grass dealt with reunification in his 1995 novel A Broad Field. His other books also tackled topics including the Vietnam war, the differences between the sexes, the nuclear threat and environmental concerns.
His political views continued to divide opinion, and he last made headlines in 2012 with a poem that warned that Israel could launch a nuclear attack on Iran and threaten world peace.
Critics accused him of anti-Semitism. The author himself said he had often supported Israel and had intended to attack the policies of its Prime Minister Benjamin Netanyahu.
But the furore was not unfamiliar for an author whose work was always topical, often political and frequently controversial.