With his gentle eyes, skeletal frame, long black beard and habitual Kalashnikov, Osama bin Laden has become the world's most reviled symbol of terror.
While his connection to this week's devastating attacks in New York and Washington has yet to be definitively established, his image has evolved in the last decade from that of financier of terror to its most prominent promoter, catalyst and mastermind.
His goal has been consistent for a decade: victory in a self-proclaimed jihad, or Islamic holy war, against the United States and its allies. Now he is suspected of having added thousands of new deaths to an already impressive terrorist toll.
As he has done before, Mr. bin Laden summoned Arab reporters on Wednesday to a compound in Afghanistan to deny responsibility for the stunning strikes while praising those who conducted them.
American intelligence officials now dismiss such denials. While they once debated Mr. bin Laden's specific connection to the terrorism his networks have spawned, they now acknowledge that this frail, squeaky- voiced Saudi has mobilized hundreds of Muslims in far-flung countries to fight and die for his embittered vision of Islam, if not for him.
But while government experts no longer dispute his influence, they do take issue with many of the myths that have been cultivated about him. Though he styles himself as a humble man of the Muslim people, he is, in fact, an unlikely spokesman for the oppressed and dispossessed. Born in the mid-1950's, the youngest of some 20 sons of a Yemeni-born Saudi construction magnate, he enjoyed a youth of wealth and privilege.
While many Saudis of his era sweltered in the desert sun, he had air-conditioned houses and private stables, and was pampered by servants. His father's close ties to King Faisal of Saudi Arabia won the family business rich contracts to rebuild mosques in Mecca and Medina. After his father's death in 1968, Mr. bin Laden inherited some $300 million.
Mr. bin Laden, who graduated from King Abdul Aziz University in Jidda in 1979 with a degree in civil engineering, was not always interested in religious politics. Associates portrayed him as a frequent visitor with Saudi royalty to Beirut, where he drank heavily at night clubs and wound up in bar brawls.
He has said he was galvanized by three events in the late 1970's: the Camp David peace accords between Egypt and Israel, the overthrow of the Shah of Iran in a radical Islamic revolution, and the Soviet incursion in Afghanistan. "I was enraged," he told the newspaper Al Quds al Arabi.
He spent the first years of the Afghanistan war traveling to raise money for the jihad against the Soviets. He moved to the Pakistani border town of Peshawar in 1984, by which time Soviet forces were encountering fierce opposition from Afghan guerrillas.
Mr. bin Laden's money earned him instant access and popularity. Abdullah Anas, a former Algerian ally who later fell out with him, said that while he was not "very sophisticated politically or organizationally," he was an activist with "great imagination." And above all, he said, he was very generous: "He'd give you his clothes."
Mr. Anas said that in Afghanistan, Mr. bin Laden fell under the influence of the Egyptian Islamic Jihad, seasoned militants who had helped assassinate President Anwar el-Sadat in 1981. They persuaded him that the jihad had to be expanded to other Muslims who were living under autocratic "infidel" regimes.
In 1986, Mr. bin Laden established the first of more than a dozen training camps he would eventually sponsor in Afghanistan, Mr. Anas and intelligence officials said.
About a year later, with the tide turning against the Soviets, he and the Egyptians founded Al Qaeda, the group base from which they hoped to stage their global Islamic crusade.
Euphoric about their victory over the Soviets, Mr. bin Laden and his extremist allies concluded that no secular state could defeat holy warriors. He opened more camps and spent more of his personal fortune, much of which the United States and its allies have now frozen, to help finance training and indoctrination to produce militants for the new borderless jihad.
While the United States had worked alongside him to help oust the Russians from Afghanistan, Mr. bin Laden turned violently anti- American in 1990 after King Fahd invited the United States and its allies to station forces in Saudi Arabia to help defend the oil-producing kingdom against an invasion by Iraq.
The presence of American soldiers in Saudi Arabia, the birthplace of the Prophet Muhammad and the home of the two holiest Muslim shrines, enraged Mr. bin Laden and other Arab militants. Over time, they increasingly came to blame the United States for Muslim woes, among them oppression of Palestinians by Israel.
After Saudi intelligence officials caught Mr. bin Laden smuggling weapons from Yemen, they withdrew his passport and pressed him into leaving the country. Mr. bin Laden made his way to Sudan, where, once again, his money earned him a warm welcome.
After the 1993 World Trade Center bombing by Muslim militants, some of whom had ties to Mr. bin Laden's network, American intelligence began focusing more intently on him.
After two terrorist attacks on Americans in Saudi Arabia in 1996, at least one of which was attributed to Mr. bin Laden, the Americans pressed Sudan to expel him. He found fertile ground for his jihad in Afghanistan, and two years later, his Qaeda organization formed an international militant Muslim coalition that formally declared that it was "the duty" of Muslims everywhere to kill Americans.
Since then, members of his network have been tied to at least a dozen successful or failed attacks that he ordered. Until now, the most deadly was the 1998 twin bombings of American embassies in Africa and the attack in Yemen on the American destroyer Cole in October 2000, in which 17 sailors died.
[In Dallas, F.B.I. officials said yesterday that they were seeking the former leader of the Islamic Society of Arlington, Tex., for questioning in Tuesday's attacks, the Associated Press reported. The man, Moataz al- Hallak, 40, has been under scrutiny for several years because of his link to Wadih el-Hage, who this year was convicted of conspiring with Mr. bin Laden for his role in the bombings of American embassies in Africa.]
After the Clinton administration attacked Mr. bin Laden's camps in Afghanistan and a pharmaceutical plant in Sudan in response to his bombings, Mr. bin Laden issued another warning. America, he said, was weak. "The battle," he said, had not yet begun.