The hard-partying playboy, known for his practical jokes and his ostentatious charisma, was obsessed with women, fast cars and jetting around the world on private planes.
At the wild parties he threw at his Florida estate, he'd fly in cases of Dom Perignon and neighbors would complain about the stench of marijuana smoke.
Who's the decadent lothario? Salem Bin Laden, the oldest brother of Osama Bin Laden.
It may be hard to believe, but despite the al-Qaeda leader's condemnation of debauchery and licentiousness, Osama looked up to and respected Salem, his polar opposite in lifestyle and temperament, who once joked that he was going to hell.
And if Salem hadn't died in a plane crash in 1988, it's possible he could have steered his younger brother away from terrorism, according to Steve Coll, the author of "The Bin Ladens: An Arabian Family in the American Century."
The two brothers, the zealot and the libertine, dominate Coll's epic account of the wealthy Saudi Arabian family whose construction industry fortune was amassed by their father, Mohamed. After their father's death in the 1960s, Salem became the patriarch of the family and was like a father to Osama, according to his mother.
"A lot of people who knew Salem believed that he would have prevented Osama for becoming so radicalized and so isolated that he would not have pulled off 9/11," Coll tells ABCNews.com.
"He had a strong relationship with Osama and sold him weapons [when Osama was funding the Afghan mujahideen in the 1980s]. Any friend of Salem's he had to treat with deference and respect."
While Osama's own mother and his uncle and other brothers failed to coax him back to Saudi Arabia from his exile in the Sudan in the mid-1990s, Coll believes that Salem would have succeeded.
"Salem would not have abided it and if it meant bundling him up in a burlap sack and taking him back to Saudi Arabia, he would have done that."
A classic example of the bond between these brothers and the distance between their lives was an elaborate hunting expedition to Pakistan that Salem envisioned as "a blend of Arabian Nights and Dr. Seuss."
For the trip with a mixed group of Europeans and Saudis, Salem brought a hot-air balloon, a four-wheel drive Volkswagen camper equipped with all types of gizmos. After stopping at his estate in London, the group flew to Salzburg, where they went skiing at Kitzbuhel and Salem bought everyone skis, boots, parkas and pants and they went to a party at a villa belonging to arms dealer Adnan Kashoggi.
Salem then flew the group to Marbella, Spain and on to Cairo for New Year's Eve. Finally, they landed in Peshawar, where they were greeted by Osama, who was helping arm the Afghan resistance. While Osama showed them refugee camps for Afghan civilians, Salem recorded the scene on video.
What Made Salem So Different
Why did Osama turn out so different from Salem?
"Salem went to boarding school in England, where he played in a rock band and he had this great adventure," says Coll. "None of his brothers had that experience, the privilege. He had that confidence of the eldest son… And he was American in his outlook on life, drawn to open spaces, to sense of play and possibility."