At 10:30 a.m. local time, a massive truck bomb explodes outside the U.S. embassy in Nairobi, Kenya. Minutes later, another truck bomb detonated outside the U.S. embassy in Dar es Salaam, the capital of neighboring Tanzania. The dual terrorist attacks killed 224 people, including 12 Americans, and wounded more than 4,500. The United States accused Saudi exile Osama bin Laden, a proponent of international terrorism against America, of masterminding the bombings. On August 20, President Bill Clinton ordered cruise missiles launched against bin Laden’s terrorist training camps in Afghanistan and against a pharmaceutical plant in Sudan, where bin Laden allegedly made or distributed chemical weapons.

Osama bin Laden was born in 1957 into one of Saudi Arabia’s wealthiest and most prominent families. His father, an immigrant from South Yemen, had built a small construction business into a multibillion-dollar company. When his father died in 1968, bin Laden inherited an estimated $30 million but for the next decade drifted without focus and lived a jet-setting lifestyle. In 1979, however, everything changed when the Soviet Union invaded Afghanistan. Like tens of thousands of other Arabs, bin Laden volunteered to aid Afghanistan in repulsing what he saw as the godless communist invaders of the Muslim country.

For the first few years of the Afghan War, he traveled around Saudi Arabia and the Persian Gulf raising money for the anti-Soviet Afghan fighters. In 1982, he traveled to the front lines of the war for the first time, where he donated construction equipment for the war effort. Bin Laden directly participated in a handful of battles, but his primary role in the anti-Soviet jihad was as financier. During the war, he made contact with numerous Islamic militants, many of whom who were as anti-Western as they were anti-Soviet.

In 1989, the Soviets withdrew from Afghanistan, and bin Laden returned to Saudi Arabia. He grew increasingly critical of the ruling Saudi family, especially after hundreds of thousands of U.S. troops were welcomed onto Saudi soil during the Persian Gulf War. Although his passport was taken away, he slipped out of Saudi Arabia in 1991 and settled in the Sudan. From there, he spoke out against the Saudi government and the continuing U.S. military presence in Saudi Arabia, which he likened to the Soviet occupation of Afghanistan.

After the 1993 bombing of the World Trade Center in New York, the United States began to suspect that bin Laden was involved in international terrorism against the United States. The military organization he built during the Afghan War–al Qaeda, or “the Base”–was still in existence, and U.S. intelligence believed he was transforming it into an anti-U.S. terrorist network. In 1995, bin Laden called for guerrilla attacks against U.S. forces in Saudi Arabia, and three months later a terrorist attack against a U.S. military installation killed five Americans. Under U.S. and Saudi pressure he was expelled from the Sudan in May 1996. One month later, a truck bomb killed 19 U.S. servicemen in Saudi Arabia. Whether or not bin Laden was involved in planning these attacks has not been established.

With 200 of his followers, bin Laden returned to Afghanistan, which was then falling under the control of the Taliban, a faction of extreme Islamic fundamentalists. Bin Laden provided funding for the Taliban military campaign against the city of Kabul, which fell to the militia in September 1996. Soon after his arrival in Afghanistan, bin Laden issued a fatwah, or religious decree, calling for war on Americans in the Persian Gulf and the overthrow of the Saudi government. In February 1998, he issued another fatwah stating that Muslims should kill Americans, including civilians, anywhere in the world.

On August 7, 1998—the eighth anniversary of the deployment of U.S. troops to Saudi Arabia—two U.S. embassies in East Africa were bombed almost simultaneously. The attack at the Nairobi embassy, which was located in a busy downtown area, caused the greater devastation and loss of life. There, a truck loaded with 2,000 pounds of TNT forced its way to the back entrance of the embassy and was detonated, shattering the embassy, demolishing the nearby Ufundi Coop House, and gutting the 17-story Cooperative Bank. By the time rescue operations came to an end, 213 people were dead, including 12 Americans. Thousands of people were wounded, and hundreds were maimed or blinded. The attack against the U.S. embassy in Dar es Saalam killed 11 and injured 85.

By 1997, American intelligence officers knew that bin Laden operatives were active in East Africa but were unable to break up the terrorist cell before the embassies were attacked. They had even heard of a possible plot to bomb the U.S. embassy in Nairobi but failed to recommend an increase in security before the attack. Meanwhile, Prudence Bushnell, the U.S. ambassador to Kenya, independently asked the State Department to move the Nairobi embassy because of its exposed location, but the request was not granted. Revelations of these pre-bombing security issues provoked much controversy and concern about the United States’ vulnerability abroad. Few, however, voiced concern that the proliferation of terrorists eager to kill innocent civilians and themselves in order to strike a blow against the U.S. would soon shatter America’s sense of invulnerability at home.

Within days of the August 7 bombings, two bin Laden associates were arrested and charged with the attacks. However, with bin Laden and other key suspects still at large, President Clinton ordered a retaliatory military strike on August 20. In Afghanistan, some 70 American cruise missiles hit three alleged bin Laden training camps. An estimated 24 people were killed, but bin Laden was not present. Thirteen cruise missiles hit a pharmaceutical plant in the Sudan, and the night watchman was killed. The United States later backed away from its contention that the pharmaceutical plant was making or distributing chemical weapons for al Qaeda.

In November 1998, the United States indicted bin Laden and 21 others, charging them with bombing the two U.S. embassies and conspiring to commit other acts of terrorism against Americans abroad. To date, nine of the al Qaeda members named in the indictments have been captured; six are in the United States, and three are in Britain fighting extradition to the United States.

In February 2001, four of the suspects went on trial in New York on 302 criminal counts stemming from the embassy attacks. On May 29, all four were convicted on all counts. Saudi citizen Mohamed Rashed Daoud al-‘Owhali and Tanzanian Khalfan Khamis Mohamed admitted to directly taking part in the terrorist attacks but claimed they did not knowingly engage in a conspiracy against the United States. Lebanese-born U.S. citizen Wadih El-Hage and Jordanian Mohammed Saddiq Odeh admitted ties to bin Laden but denied involvement in any terrorist acts. All four were sentenced to life in prison without parole.

On September 11, 2001, the world learned that the U.S. embassy attacks were merely a prelude to a far more devastating strike against the United States. On that day, 19 al Qaeda terrorists deftly exploited weaknesses in U.S. domestic security and hijacked four U.S. airliners that they flew into the World Trade Center towers in New York; the Pentagon in Arlington, Virginia; and a rural field in western Pennsylvania. Four thousand people were killed in the almost simultaneous attacks and 10,000 were wounded. On October 7, America struck back with Operation Enduring Freedom, the U.S.-led international effort to oust the Taliban regime in Afghanistan, destroy the al Qaeda network based there, and capture bin Laden dead or alive.

On May 2, 2011, bin Laden was killed by U.S. Navy SEALs. He was buried at sea.