The fast and loose financial climate gnawed at his mother. “I said to Misha, ‘All businessmen in Russia will end up in prison or dead. I’ve seen it happen before. This is in our history,’ ” Marina Khodorkovsky tells me one afternoon at her modest yellow house outside Moscow. “But Misha said, ‘No. It will be different this time. We will be like the West.’ ” She pauses. “I never wanted him to be a businessman.”

During the 1990s, Russia was a mess. The economy was tanking, there was a costly war in Chechnya, and gangsters had infiltrated many of the nation’s businesses. Russian President Boris Yeltsin, in an effort to save his skin, called in a dozen or so up-and-coming capitalists, including Khodorkovsky. In a transaction known as loans for shares, the tiny group of influential men essentially bankrolled the president’s reelection battle in return for their pick of Russia’s oil fields, telecommunications firms, banks, and gold mines.

Khodorkovsky wanted oil—particularly Yukos. At the time, the company wasn’t in great shape, nor was the country’s oil industry, which had become a rusting hulk saddled with corruption and inefficiency. Equipment was outdated, managers siphoned off profits or paid protection money to Mob bosses, and employees spent more time swilling vodka than working.

The 1995 Yukos auction was a classic example of Yeltsin-style privatization. Western companies were forbidden to participate, and a Russian company—a rival of Khodorkovsky’s—was mysteriously disqualified despite offering more money. In the final agreement, Khodorkovsky, whose own Bank Menatep arranged the auction, won a 78 percent stake in Yukos for $350 million. Included in the deal was the company’s $3 billion of debt. Two years later—after the company wrested control from Soviet-era oil bosses, centralized power, and mandated that anyone caught drinking on the clock be fired—Yukos shares began trading on the Moscow stock market, and the company had a market capitalization of $9 billion. ­Yukos was seen as a rising force.

The money brought Khodorkovsky and his fellow titans exceptional power, with huge influence in the Kremlin, especially after Yeltsin’s manufactured electoral victory. Like other industry kings, Khodorkovsky traveled with bodyguards in armed luxury cars. He married, had four kids—his oldest recently graduated from college and works in advertising in New York—and helped build a gated community in the Moscow suburbs for himself and his partners.

Khodorkovsky could occasionally come off as ruthless. He funneled profits and shifted ownership rights to offshore accounts, moved forcefully against corporate raiders, and exploited minority investors. His climb continued through the 1997 financial collapse and the oil-price surge that followed. All was good until Vladimir Putin, the former K.G.B. agent, came to power on New Year’s Eve 1999.

The story of KhodoRkovsky’s fall begins in July 2000, seven months after Putin succeeded Yeltsin. That month, the new president summoned the oligarchs to the Kremlin, where, in a quiet room, Putin declared an end to gangster capitalism. The 1990s were history, he announced. It was time for reform. He issued a warning: Keep clear of politics, and you won’t be questioned about the murky methods by which you became so rich. But cross me and you will be buried.

Out of this, three types of oligarch emerged: those who remained neutral in relation to Putin—for instance Vagit Alekperov, who owned a controlling stake in Lukoil; those who became Putin’s allies, such as Roman Abramo­vich, who had investments in oil and steel; and those who decided to fight. Khodorkovsky fell into the last camp.

For a time, he appeared to be safe. He transformed Yukos into a Western-style powerhouse and hired American oil executives to modernize his books. In 2001, he organized the Open Russia Foundation, a nonprofit that spent millions of dollars advocating investments in democracy, economic transparency, and human rights. Bruce Misamore, the American chief financial officer of Yukos at the time, tells me that the oligarch was on a mission. “I don’t know if you would call it a revelation, but he changed,” Misamore says. “He brought in McKinsey, Schlumberger, Halliburton, and decided to become a model.”