With the death of his father in 1971, Mr. Bronfman’s personal life began to unravel. That same year he separated from his wife, with whom he had five children. After their divorce, he married Lady Carolyn Townshend, in 1973, but that marriage also ended in divorce, a year later. He quickly became involved with another Englishwoman, Rita Webb (who changed her name to Georgiana). They married and divorced each other twice, and had two daughters. He then married Jan Aronson, an artist and a former triathlete.

He is survived by Ms. Aronson; his sons, Samuel, Edgar Jr., Matthew and Adam, and his daughter Holly Bronfman Lev, all from his first marriage; his daughters with Ms. Webb, Sara Igtet and Clare Bronfman; his brother, Charles; his sister Phyllis Lambert; 24 grandchildren; and two great-grandchildren.

In 1975, Samuel Bronfman II was kidnapped in New York and held for ransom. Mr. Bronfman himself delivered the $2.4 million ransom to one of his son’s two kidnappers, who were both arrested shortly afterward by the F.B.I. But the kidnappers’ lawyer claimed in court that the abduction had been a hoax and that Sam Bronfman had been a part of it. In the end, the jury convicted the defendants of the lesser charge of extortion. With liquor consumption in decline in 1981, Mr. Bronfman tried to buy Conoco, a major oil and gas company. Seagram lost out to DuPont in the bidding but, because of its investment in Conoco, ended up with a 20 percent share of DuPont — and soon raised this to almost 25 percent, making Seagram DuPont’s largest minority shareholder.

Initially, most Wall Street analysts and the financial press took the position that Seagram had been outdueled for Conoco by DuPont. A 1981 Business Week article quoted a DuPont senior executive as saying jokingly that he enjoyed drinking “Seagram on the rocks.” But by 1985 its stake in DuPont accounted for nearly 75 percent of Seagram’s earnings, and Mr. Bronfman was being hailed as a smart, risk-taking businessman.

At the same time, Mr. Bronfman was becoming increasingly involved in Jewish causes. He was elected president of the World Jewish Congress in 1981. “Making money is marvelous, and I love doing it, and I do it reasonably well,” he told The New York Times in 1986, “but it doesn’t have the gripping vitality that you have when you deal with the happiness of human life and with human deprivation.”