His works are frequently considered to have a left-wing political dimension, and Grass was an active supporter of the Social Democratic Party of Germany (SPD).

In 1999, the Swedish Academy awarded Grass the Nobel Prize in Literature, praising him as a writer "whose frolicsome black fables portray the forgotten face of history".

In November 1944, shortly after his 17th birthday, Grass volunteered for submarine service with Nazi Germany's Kriegsmarine, "to get out of the confinement felt as a teenager in his parents' house", which he considered stuffy Catholic lower middle-class.

[20] Grass's best-known work is The Tin Drum (Die Blechtrommel), published in 1959 (and adapted as a film of the same name by director Volker Schlöndorff in 1979).

[28] In My Century (Mein Jahrhundert, 1999) Grass covered many of the 20th-century's brutal historic events, conveyed in short pieces of a few pages by year, forming a mosaic of expression.

It dealt with the events of a refugee ship, full of thousands of Germans, being sunk by a Soviet Russian submarine, killing most on board.

Titled Peeling the Onion (Beim Häuten der Zwiebel), it dealt with his childhood, war years, early efforts as a sculptor and poet, and finally his literary success with the publication of The Tin Drum.

In a pre-publication interview, Grass revealed for the first time that he had been a member of the Waffen-SS, and not only served as a Flakhelfer (anti-aircraft assistant), as he had long claimed.

On being asked about his decision to make a public confession, he answered: "It was a weight on me, my silence over all these years is one of the reasons I wrote the book.

"[30] In response to the interview and the book, many critics accused him of hypocrisy for having hidden this part of his past, while simultaneously being a strong voice for ethics and morality in the public debate.

[30] The book was praised for its depictions of the German postwar generation, and the social and moral development of a nation burdened simultaneously by destruction and a deep sense of guilt.

His works also show a sustained concern for the marginal and marginalized subjects, such as Oskar Matzerath, the dwarf in The Tin Drum, whose body was considered an aberration unworthy of life in the Nazi ideology, or the Roma and Sinti people deemed impure and unworthy by the Nazis and subjected to eugenics and genocide, as were the Jews.

[35][36] Grass's work has tended to divide the critics into those who have considered his experiments and style to be sublime and those who have found it to be tied down by his political posturing.

American critics, such as John Updike, have found the mixture of politics and social critique in his works to diminish its artistic qualities.

Grass expressed his concern about the hypocrisy of German military support (the delivery of a submarine) of Israel, which might use such equipment to launch nuclear warheads against Iran, which "could wipe out the Iranian people".

And he hoped that many would demand "that the governments of both Iran and Israel allow an international authority free and open inspection of the nuclear potential and capability of both."

[43][44][45] According to Avi Primor, president of the Israel Council on Foreign Relations, Grass was the only important German cultural figure who had refused to meet with him when he served as Israeli ambassador to Germany.

According to his publisher Gerhard Steidl, the book was "a literary experiment", combining short prose texts, poems, and pencil drawings by the writer.

[7] His literature is commonly categorized as part of the German artistic movement known as Vergangenheitsbewältigung, roughly translated as "coming to terms with the past."

[53] In 1992, he received the Hidalgo Prize, awarded by the National Association of Spain "Presencia Gitana", in recognition of his defense of the Romani People.

[55] In August 2006, in an interview to the Frankfurter Allgemeine Zeitung about his forthcoming book, Peeling the Onion, Grass said that he had been a member of the Waffen-SS in World War II.

[57] After an unsuccessful attempt to volunteer for the U-boat fleet in 1942, at age 15, Grass had been conscripted into the Reichsarbeitsdienst (Reich Labor Service).

Grass was trained as a tank gunner and fought with the 10th SS Panzer Division Frundsberg until its surrender to US forces at Marienbad.

[58][59] In 2007, Grass published an account of his wartime experience in The New Yorker, including an attempt to "string together the circumstances that probably triggered and nourished [his] decision to enlist.

"[60] As Grass was for many decades an outspoken left-leaning critic of Germany's failure to deal with its Nazi past, his statement caused a great stir in the press.

Rolf Hochhuth said it was "disgusting" that this same "politically correct" Grass had publicly criticized Helmut Kohl and Ronald Reagan's visit to a military cemetery at Bitburg in 1985, because it contained graves of Waffen-SS soldiers.

[61] Joachim Fest, a biographer of Adolf Hitler, remarked on Grass's disclosure: "After 60 years, this confession comes a bit too late.

Jacek Kurski, a Law and Justice politician, said, "It is unacceptable for a city where the first blood was shed, where World War II began, to have a Waffen-SS member as an honorary citizen.

[71] An avid pipe smoker for most of his adult life, Grass died at the age of 87 of a lung infection on 13 April 2015 in a Lübeck hospital.

Among those who attended were German President Joachim Gauck, former Chancellor Gerhard Schröder, federal Commissioner for Culture Monika Grütters, film director Volker Schlöndorff, and Paweł Adamowicz, mayor of Gdańsk.