Günter Grass, a German author whose works explored national guilt and atonement for Germany’s involvement in World War II, died on Monday, April 13, at a hospital in Lübeck, Germany. He was eighty-seven.

His longtime publisher, Gerhard Steidl, did not report a cause of death.

Grass received the Nobel Prize in 1999 for his novel, The Tin Drum, which features an intelligent, but stunted boy, Oskar Matzerath, who supposedly symbolizes the country’s stunted morality during and after Nazism. The Swedish Academy praised Grass for completing “the enormous task of reviewing contemporary history by recalling the disavowed and the forgotten: the victims, losers, and lies that people wanted to forget because they had once believed in them.”

In addition to being a playwright, essayist, short story writer, poet, sculptor, and printmaker, Grass was a strident critic of public affairs, including Germany’s government. When the Berlin wall was breached in 1989, Grass argued in a 1990 speech against German unification, arguing that “Auschwitz speaks against even a right to self-determination that is enjoyed by all other peoples, because one of the preconditions for the horror, besides other, older urges, was a strong and united Germany.”

In 2006, however, his status as the “moral conscience” of Germany came under fire when he revealed a few days before the publication of his memoir, Peeling the Onion, that he was a member of the Waffen SS, the military branch of the Nazi corps. He was seventeen when he was drafted and assigned to the 10^th SS Panzer Division.

The admission led many to question why Grass hid this aspect of his personal history while persecuting others. “I do not understand how someone can elevate himself constantly for sixty years as the nation’s bad conscience, precisely in Nazi questions, and only then admit that he himself was deeply involved,” said Joachim Fest, a prominent historian and biographer of Hitler, to the newspaper Bild.

Asked why he confessed, Grass admitted, “It weighed on me. My silence during all these years is one reason that led me to write this book. It had to come out.”

Writer John Updike, however, defended Grass’s courage: “You remain a hero to me, both as a writer and a moral compass,” he wrote.

Grass was born in Danzig—then, under the control of League of Nations, but now the Polish city of Gdansk—on Oct. 16, 1927, to a German father, and a mother who was Kashubian. He joined the Nazi children’s organization Jungvolk at the age of ten, which included Joseph Ratzinger, who went on to become Pope Benedict XVI. Grass and Ratzinger later became prisoners in an Allied camp at Bad Aibling.

When Grass returned to civilian life, he was drawn to art and poetry, and joined a circle of critical intellectuals known as Group 47. He wrote several books, and The Tin Drum’s fame grew when director Volker Schlöndorff made the book into a film, which received the 1979 Academy Award for best foreign language film.