We also learn that Jim Bath, a former reserve pilot with the Texas Air National Guard who used to carouse with George W. Bush, later became a business partner in Houston with Salem bin Laden, Osama’s half-brother.

The ultimate self-made man, the family patriarch Muhammad bin Laden left an impoverished and deeply religious canyon village to seek his fortune (during an early interlude in the pilgrim city of Jeddah, he was so poor that he reportedly slept in a ditch he dug in the sand) and through a combination of skill, acumen and the assiduous cultivation of the royal family, became the king’s principal builder, overseeing renovations of sacred sites in Mecca, Medina and Jerusalem. He would bequeath to his children not just a fortune, but also what Mr. Coll calls a “transforming vision of ambition and religious faith in a borderless world.” His British-educated son, Salem, who took over the company after his death, would expand its international reach, and he would also embrace a Westernized, jet-set existence that allowed him to indulge his eccentricities to the fullest.

In fact, Salem emerges from this volume as a compelling, larger-than-life figure, a picaresque playboy, at once guileless, brilliant and self-indulgent, who held together the increasingly fractious bin Laden clan through sheer force of will and charisma. Salem, who dressed in jeans, loved airplanes and liked to play the harmonica, reportedly “paid a bandleader at an Academy Awards party in Los Angeles hundreds of dollars to let him sing ‘House of the Rising Sun’ in seven languages.”

Mr. Coll reports that Salem organized family expeditions to Las Vegas, shipped thousands of cases of Tabasco sauce back to Saudi Arabia and dreamed of marrying four women from four Western nations: his estate, he imagined, would resemble the United Nations, with four houses, one flying an American flag, one a German flag, one a French flag and one the Union Jack. Salem died in 1988 in a plane accident in Texas.

Image Steve Coll Credit... Lauren Shay Lavin

As for Osama bin Laden, Mr. Coll, like Mr. Wright in “The Looming Tower,” suggests that the Qaeda founder’s turn to international war against the United States was not inevitable. Mr. Coll writes that when the Saudi royal family agreed in the summer of 1990 to the arrival of American troops in response to Iraq’s invasion of Kuwait, Mr. bin Laden “offered no public dissent” at the time, but “moved quickly with the rest of his family to protect his personal fortune against the possibility that the Al-Saud regime might collapse.” Although he had come to see himself as an “international Islamic guerrilla leader,” his views at the time, Mr. Coll writes, were still “nuanced, changeable and laced with contradictions.”

Increasingly at odds with the Saudi royal family, Mr. bin Laden left the kingdom in 1991 for the Sudan, where he bought a farm and raised horses and sunflowers while training jihadis (whom he sent to places like Bosnia). “Osama seemed to believe during this period,” Mr. Coll writes, “that he could have it all in Sudan  wives, children, business, horticulture, horse breeding, leisure, pious devotion and jihad  all of it buoyed by the deference and public reputation due a proper sheikh. He did not yet seem to grasp that his enterprise, particularly in its support for violence against governments friendly to or dependent upon the Al-Saud, might prove difficult to reconcile with the interests of his family in Jeddah.”