Publisher and philanthropist Lord Weidenfeld has died aged 96.
The peer died "peacefully in his sleep" on Wednesday morning following a brief illness, his family said in a statement.
He is expected to be buried in Israel.
In a tribute, Israeli Prime Minister Benjamin Netanyahu said Lord Weidenfeld had traveled "a unique path from refugee to peer".
He added: His countless personal achievements were always accompanied by his remarkable work for the benefit of the Jewish people, the State of Israel and humanity as a whole. He will be remembered as an innovative publisher of important works and for his dedication to higher education in Israel, the United Kingdom and across Europe."
Chief Rabbi Ephraim Mirvis said Lord Weidenfeld was "a towering figure in the Jewish community whose legacy will be one of great compassion".
Chief Rabbi Pinchas Goldschmidt, Conference of European Rabbis president, said: "Lord Weidenfeld was a man who epitomised community service and leadership whilst his perception of the new challenges facing Europe was both unique and powerful.
"One of Lord Weidenfeld’s last acts, rescuing Christian families from Syria and Iraq and resettling them elsewhere exemplifies the legacy of a man we should all endeavour to replicate."
Born in Vienna in September 1919, George Weidenfeld attended the University of Vienna.
Following the Nazis’ annexation of Austria he emigrated to London, where he initially worked for the BBC.
By 1942, he was a political commentator and later started his own publishing firm, Weidenfeld & Nicolson with Nigel Nicolson.
Notable works published by the firm included Lolita, by Vladimir Nabokov, and memoirs by Golda Meir and Yitzhak Rabin.
Lord Weidenfeld spent a year as political adviser to Israel’s first president, Chaim Weizmann, in 1949.
He was knighted in 1969 and made a life peer in 1976.
In 2015, aged 95, the peer funded a rescue mission for Christians in Syria and Iraq – the Weidenfeld Safe Haven Fund. It flew 150 people to Warsaw in July.
At the time he said: “I can’t save the world… but I had a debt to repay. It was Quakers and Christians who brought those [Kindertransport] children to England. It was a very high-minded operation and we Jews should also be thankful and do something for the endangered Christians.”
He said that he hoped to mirror the work done by Sir Nicholas Winton, who helped 669 children escape from Nazi persecution.
Lord Weidenfeld was one of the most decorated Jews in Britain – he was awarded a GBE, which had only ever been given to three other Jews: Herbert Samuel, Victor Rothschild and Jacob Rothschild.
He had honorary doctorates from Oxford, Exeter University and King's College; Fellowships of St Anne's and St Peter's Colleges, Oxford; a post as a Senator of Bonn University; an honorary degree from Vienna University; and the highest orders in Germany, Italy and Austria.
Emeritus Chief Rabbi Lord Sacks said: "George Weidenfeld was so much larger than life, and so inexhaustible in energy, that it is hard to believe he is no longer with us.
"I knew him not only as a publisher, a connector, a man who seemed to know everyone, but as an elemental force for good.
"He was always thinking of new ways to fight prejudice, heal ancient wounds, and bring peace to troubled regions of the world.
"Even in his 90s he seemed constantly to be coming up with new projects, among them a series of university professorships to advance peace in the Middle East, and a plan to rescue 20,000 endangered Christians from Syria as a way of thanking Christians who saved Jewish lives in the Holocaust.
"Every few months he would be on the phone with another brilliant idea – and, whatever he undertook to do, he did. He was bold, he was visionary, he was hard working, and he was fun. He was a giant, and without him the world will seem a smaller and less vivid place.”
Sir Mick Davis, Jewish Leadership Council chairman, said: "Lord Weidenfeld was a leader, thinker and businessman whose thoughts and understanding of our changing world were sought after by leaders the world over.
"He had a broad view of the world and how it could be shaped for the benefit of mankind. He was innovative and tireless in his search for solutions to the challenges of our time.
"He was a remarkable philanthropist and amongst his last acts was the rescuing and resettling of Christian families from Syria and Iraq. That epitomises his legacy.
"I am deeply saddened by his loss but take comfort that we are all better off for his extraordinary contribution to this country and society across the world.”
Board of Deputies president Jonathan Arkush said: “I am very saddened to hear about the death of Lord Weidenfeld.
"He was a tireless worker for Israeli, Jewish and other causes and a philanthropist who only last year funded a rescue mission for Christian Syrians.
"His energy, charm, warmth and intelligence will be remembered by all who met him.”
Lord Weidenfeld leaves a widow, Lady Weidenfeld, a daughter, Laura, grandchildren and great-grandchildren.