Shattered dynasty.(legal wrangling between Jay Pritzker's family members over inheritance)

Jay Pritzker quietly built a $15 billion empire of more than 200 companies, including Hyatt Hotels Corp., and a network of 1,000 family trusts. But one of the patriarch's final deals before his 1999 death, designed to bind his heirs closer, unleashed a torrent of anger, greed, and betrayal, culminating last fall in a $6 billion lawsuit by his 19-year-old niece, Liesel. SUZANNA ANDREWS charts the destruction of a great American fortune

It is a simple moment that stands out most vividly in the memories of Jay Pritzker's friends-a moment during his funeral which did not seem to them remarkable at the time, but which in retrospect was the last time they saw his family united. "It was a very cold day and there was snow," one friend recalls. Because of the weather, many guests had not been able to make it to Chicago that day in January 1999; still, nearly 1,000 mourners had shown up at the Emanuel Congregation to pay their respects, forcing the police to barricade part of North Sheridan Road to make way for the limousines. Chicago's mayor, Richard Daley, had come, as had the former congressman Jack Kemp, the real-estate billionaire Sam Zell, and the advice columnist Ann Landers, along with scores of investors and businessmen with whom Pritzker had dealt in the decades during which he amassed one of the largest fortunes in America. The former director of the National Gallery of Art J. Carter Brown, who, before his death last year, chaired the jury of the famed Pritzker Architecture Prize, was there. And so were representatives of the countless hospitals, cultural groups, and charities to which Pritzker had, before he died at the age of 76, given hundreds of millions of dollars. "The temple was filled," says one of Jay Pritzker's friends.

At the front of the synagogue, taking up several rows of seats, were almost all of the 52 living members of the Pritzker family. For many of the mourners, it was the first time they had seen so many of the publicity-shy clan in public. Intensely private, they are rarely photographed or interviewed, almost never seen. Marian "Cindy" Pritzker, Jay's wife of 51 years, and his younger brother and business partner, Robert, were seated in the front row, flanked by Jay's three sons, Thomas, John, and Daniel, and his daughter Gigi. With cousins surrounding them in a protective phalanx, they formed a tableau that Jay Pritzker, friends say, would have loved. In life, they say with sadness now, nothing was more important to him or gave him more joy than his family.

All three of Jay's sons spoke at his funeral that day. They spoke about his passions for skiing and buying companies, and about how much they loved him. "I've lived a privileged life, and truly the greatest privilege was getting to know Dad in my adult years," said Daniel, a rock musician, who is now 43. "Growing up was kind of like having Chuck Yeager and John Glenn for a dad," said John, now 49 and an entrepreneur in San Francisco. And then Tom, Jay's oldest son, stood up to speak. It was Tom, now 52, to whom Jay had passed the torch; Tom controlled the family's empire-including its crown jewel, the Hyatt Hotels Corp., the Pritzkers' web of more than 200 privately held companies, vast tracts of real estate, and some 1,000 family trusts, all of which, taken together, are said to be worth $15 billion, if not more. His father, Tom told the crowd, "believed a man's only immortality comes from the values he instilled in his children. The country has lost a great man. I've lost my father. I've lost my partner. I've lost my best friend." As he spoke, Tom began to cry.

The day of his funeral was the last time that many of Jay Pritzker's friends saw his three sons together. The moment that sticks in their memories is how lovingly his sons spoke of their father-because what they did next would surely have destroyed him.

The first hint of trouble came last November. Just before Thanksgiving, Robert's 19-year-old daughter, and Jay's niece, Liesel Pritzker-a Columbia College freshman and an actress who starred alongside Harrison Ford as the president's daughter in the 1997 movie Air Force One and who is currently appearing in the Broadway play Vincent in Brixton-filed a lawsuit in Chicago against her father and all the Pritzker cousins. Setting off an explosion of publicity, she accused her family of looting her trust funds and those of her 20-year-old brother, Matthew, in a way that was "so heinous, obnoxious and offensive as to constitute a fraud." The amount of money which Liesel claimed was taken from her was staggering-$1 billion-and she not only demanded it be returned, but asked the court to award her $5 billion in punitive damages. It was a stunning lawsuit, not just because of the money involved, but also for the questions it raised about the Pritzkers. What could have happened within a family, people asked, that would lead a young woman to sue her 76-year-old father and go public with such ugly accusations?

As Liesel's case moved forward, it brought to light something more disturbing. In a confidential agreement made in 2001, Jay Pritzker's children, his nieces and nephews, and his cousin Nicholas had decided on a 10-year plan to break up the family's business empire and split the assets among themselves. Each of those who participated in the agreement would reportedly get an equal share-estimated at $1.4 billion. Liesel and her brother were the only cousins not included in the secret pact.