Historian

Born: February 2, 1926;

Died: May 18, 2016

FRITZ Stern, who has died aged 90, was a refugee from Nazi Germany who became a prominent historian, government adviser and a longtime professor at Columbia University. In the early 1990s, he was an advisor to Margaret Thatcher on German reunification, which he supported.

He was born in the former German province of Silesia (now in Poland) to a prominent family that had converted from Judaism to Christianity. But the Sterns felt increasingly menaced by Hitler's reign and left for New York, where he received an undergraduate and master's degree and PhD from Columbia. He taught there for more than 40 years, specialising in European history, before retiring in 1997. He also briefly served as provost.

In books, essays, interviews and lectures, he investigated the rise of Nazism and the threats to democracy: On occasion, he advised government officials. In 1993, he took a leave of absence from Columbia after being appointed a senior aide to his friend Richard Holbrooke, the US ambassador to Germany.

Born in Breslau in Poland, his family left for New York in 1938 – his relatives who did not leave perished in Auschwitz. In America, one of their family friends was Albert Einstein who recommended to the young Fritz that he should study medicine. However, Fritz had history on his mind.

Stern's books included The Politics of Cultural Despair, The Failure of Illiberalism and Five Germanys I Have Known. He was also a frequent commentator on current events. In a 2004 speech, he spoke of parallels between the Nazis and the Christian right and earlier this year, he told The History News Network that presumptive Republican presidential nominee Donald Trump was a symptom of the dumbing down of the country.

"When I arrived in this country, Franklin Roosevelt was the president," he said. "That someone like Trump, who is a nobody except for his money, immense ambition and ugliness, is not only offering himself but is actually accepted by many people as a candidate, is simply incomprehensible."

On news of Stern’s death, the German President Joachim Gauck described him as a historian of great erudition and a wise, great person. "Fritz Stern rightly demanded of us Germans that the crimes against the Jews be preserved in our collective memory, to honour the victims, to learn from this rupture of civilisation, and to develop standards for shaping the present," Gauck wrote. He added that Stern served peace by building bridges of understanding between times and people and pointed to his interest in reconciliation between Germans and Poles.

His survivors include Sifton, his second wife, two children and three stepchildren, among them New York Times editor Sam Sifton.