Edgar Bronfman: Businessman who as head of the World Jewish Congress devoted his private life to championing Jewish causes

Bronfman in 2006, at the opening of a new main synagogue in Munich (EPA)

Edgar Bronfman was a restless, imaginative business leader who presided over what was once the largest liquor group on earth. The Seagram Company, however, is no more, sold to the French group Vivendi in 2000 amid an unhappy foray into the entertainment industry by his son and successor, Edgar Jr. The elder Edgar's real legacy is his quarter-century tenure as president of the World Jewish Congress, which he turned into the pre-eminent institution representing the Jewish diaspora, and a champion of Jewish causes, from the right of emigration from the Soviet Union to the restitution of assets lost during the Holocaust.

Edgar Bronfman Sr was born into one of Montreal's wealthiest Jewish families. His father Samuel, who had emigrated to Canada to flee the pogroms of czarist Russia, had created the Seagram-Distillers empire, and thrived mightily as much of output was bootlegged into the US during prohibition. The son's childhood was often an unsettling tug-of-war between two worlds: the elite Protestant schools to which he was sent by his father, and the Hebrew studies and synagogue upon which Samuel also insisted. "The fact of our Jewishness was never in doubt," he later wrote, "but the contradictory ways in which it found expression created a deep ambivalence in me that took many years to resolve."

The young Edgar started his career at the family business in 1951, first in accounts, then at the distilling plant to learn the whisky-maker's craft. By 1955, aged 26, he had transferred to the US to head Seagram's American operations, its main source of revenue. Four years later he became a US citizen. From his new base in New York Bronfman led Seagram's international expansion and diversification.

In 1971 his father died and Edgar became chairman. He held the job for 23 years, cutting an elegant figure in Manhattan society as he moved Seagram into the oil and movie industries, acquired the soft drinks manufacturer Tropicana and secured a 25 per cent stake in the Du Pont chemicals company.

In 1994 he handed the reins to Edgar Jr, but Jewish affairs had already become his consuming interest, kindled by a 1970 trip to lobby the Kremlin to allow Jews greater rights in the Soviet Union, the successor state to the imperial Russia which his grandparents and father had fled. "My curiosity was piqued," he explained later. "What is it about Judaism, I asked myself, that has kept it alive through so much adversity while so many other traditions have disappeared? Curiosity soon turned into something more, and that 'something more' has since turned into a lifelong passion."

In 1981 he was elected president of the World Jewish Congress, founded in 1936 in Geneva as an umbrella organisation for Jewish communities around the world. For some while it had stagnated, but Bronfman revived it with a vengeance, appointing his long-time associate Israel Singer as deputy and plunging into a variety of high-profile and Holocaust-related issues. In 1982 he became the first representative of any Jewish organisation to address the United Nations. Three years later he was the first official spokesman of world Jewry to travel to Moscow, where he met the new reformist leader Mikhail Gorbachev and pressed for the release of the 'Prisoners of Zion' – Soviet Jews jailed merely for having expressed the wish to emigrate to Israel.

Several such trips followed, in which Bronfman fought for further concessions, including the right of Jews to practice their religion and for Hebrew to be taught in schools. His approach was unrelenting but essentially that of a businessman constructing a deal beneficial to both sides. "By their actions," he said at the time, "they [the Soviets] are indicating that they are eager to get the question of Jewish rights and emigration off the bargaining table."

Simultaneously, the WJC was becoming a scourge of individuals and countries compromised by the Holocaust. In 1986 it helped uncover the Nazi past of Kurt Waldheim, the Austrian president and former Secretary General of the UN, accusing him of concealing his knowledge of crimes against Jews. Then Bronfman led the battle to obtain restitution by the Swiss banks of assets deposited with them by Jews murdered during the Holocaust. The campaign produced a $1.25bn settlement for surviving relatives, as well as vast embarrassment for Switzerland, exposing that country's less-than-heroic attitude to the Nazis.

Despite the unravelling of the Seagram empire, Bronfman's 2011 net worth was estimated by at $2.6bn. A notable philanthropist, he gave large sums to Jewish causes, including Hillel, the global Jewish campus organisation. He also ran the Samuel Bronfman foundation, named after his father and dedicated to bringing about a "Jewish Renaissance". He also found time to produce four autobiographical books.

But his reign at WJC closed in controversy, when he fired his old lieutenant Singer after allegations of financial mismanagement and resigned himself soon after, in 2007. His family life could be turbulent as well. Bronfman married four different women (one of them twice), and upset Samuel, his eldest son, by appointing his younger brother Edgar to take over in the family business.

Two decades earlier, in 1975, Samuel himself made headlines when he was abducted in New York and held for ransom, and his father personally delivered the $2.4m payment to the two kidnappers. But the affair was murky, with allegations that young Sam had been complicit in his abduction. Ultimately, the defendants were convicted on a lesser charge of extortion.

To the end Bronfman was a staunch supporter of moderate politicians in Israel, and of a peace deal with the Palestinians. His focus, however, began to shift from correcting past wrongs against Jews to preserving a special identity for his people. "We are not in crisis because of anti-Semitism," he told The New York Times in 2008. "We are in crisis because we are disappearing through assimilation."

Edgar Miles Bronfman, businessman and philanthropist: born Montreal 20 June 1929; Chairman and Chief Executive, Distillers-Seagram 1971-1994; President, World Jewish Congress 1981-2007; US Presidential Medal of Freedom 1999; married 1953 Ann Loeb (divorced 1973; four sons, one daughter), 1973 Carolyn Townshend (divorced 1974), thirdly and fourthly Rita Webb (marriages dissolved; two daughters), 1994 Jan Aronson; died New York 21 December 2013.