When Soviet tanks rolled into Kabul in 1979, Afghanistan was thrust into the international spotlight. But what the invasion exposed -- the strategic designs of outside powers and shifting internal alliances based on religion, ethnicity and personal loyalty -- was only the latest installment in a centuries-old cycle of violence.

The Persian King Darius I and Alexander the Great used the region as a gateway for invasions of the Indian subcontinent. Genghis Khan and Tamerlane followed in the 13th and 14th centuries, annexing part of the region -- then known as Bactria -- into their vast empires.

By the 19th century, Afghanistan had become the chess board on which a struggle for control of Central Asia would play out between imperial Britain and Czarist Russia -- a conflict author Rudyard Kipling dubbed "The Great Game."

After two disasterous campaigns against Afghan tribesman (1839-1842 and 1878-1880), Britain in 1893 signed an agreement granting Afghanistan autonomy and establishing the so-called "Durand Line" as a border with British India (present-day Pakistan).

Following a third Anglo-Afghan war in 1919, Afghanistan gained full independence. For the next half-century an Afghan monarchy managed to keep the peace with neighboring countries and among the nation's rival ethnic groups, but provided little in the way of economic development.

During the Cold War, King Mohammed Zahir Shah forged close ties with the Soviet Union, accepting extensive assistance from Moscow.

Zahir Shah's tenuous hold on power was ended in 1973, when his cousin Mohammed Daoud seized power. Daoud was ousted in a military putsch in April 1978.

In a year of extreme political instability, President Noor Taraki was killed and replaced by Hafizullah Amin, who was himself the victim of a coup three months after taking power. Amin was succeeded by Babrak Karmal, who came under intense pressure from armed Islamic insurgents opposed to his communist regime.

Fearing his government was on the verge of collapse, Karmal requested Soviet military backing. Moscow answered with a full-scale invasion in December 1979.

The Soviets were met with fierce resistance from groups already energized by opposition to the Karmal government. The guerrilla forces, calling themselves mujahedeen, pledged a Jihad -- or holy war -- to expel the invaders.

Initially armed only with outdated weapons, the mujahedeen became a focus of the Reagan Administration's Cold War policy against the U.S.S.R. Washington began providing arms -- including sophisticated surface-to-air missiles -- with Pakistan providing the logistical pipeline into Afghanistan.

Among the forces supported by Washington was a group led by a wealthy Saudi named Osama bin Laden, who, like many Middle Eastern Muslims, answered the call for Jihad by traveling to Afghanistan and taking up arms.

Moscow's forces, which peaked at more than 100,000, soon were bogged down in a no-win situation reminiscent of the U.S. experience in Vietnam. In 1986, frustrated with the stalemate, the Soviets forced Karmal to resign and installed Najibullah as president.

After nearly a decade of fighting that killed at least 15,000 Soviet soldiers, Moscow withdrew from Afghanistan in 1989.

Following the pullout, the dozens of mujahedeen factions that had fought Soviet troops turned their guns on one another even as they vied for the honor of toppling Najibullah.

By 1992, a coalition of forces dominated by ethnic Tajiks fought its way into Kabul and established the Islamic Republic of Afghanistan under the leadership of President Burhanuddin Rabbani. Najibullah fled to the United Nations mission in Kabul where he would live for another four years in internal exile.

Rabbani's hold on power remained tenuous, however, with other mujahedeen factions constantly battling to overthrow him. In the process, devastating attacks all but leveled the capital Kabul.

Sometime in 1994, a mysterious new force calling itself Taliban ("religious students") appeared on the canvas of Afghanistan's civil war. The core of the militia traced its roots to Muslim seminary schools in western Pakistan. Nearly all of the original warriors were Pashtun, the largest of Afghanistan's various ethnicities.

Islamic zeal and what many believe was substantial funding from neighboring Pakistan and from Saudi Arabia propelled the Taliban. The movement vowed to crush Afghanistan's warring factions, unify the country, and end a decade of conflict.

Over the next two years, the group systematically extended its zone of control, sometimes by force, but mostly by bribing local warlords into surrendering their strategic outposts.

Wherever they seized power, the Taliban imposed a strict brand of Islamic law, prohibiting women from working or going to school and requiring them to be veiled from head-to-toe. In the Islamic custom, men were ordered to grow beards. Music and photography were outlawed.

Although they were initially welcomed by many ordinary Afghans as harbingers of peace, the strictures imposed by the Taliban sparked resentment in some of the areas they captured.

The Taliban's methods, however, were met with Osama bin Laden's approval. The Saudi millionaire returned to Afghanistan in May 1996 aboard a chartered flight with his wives, children and about 130 followers.

Afghanistan proved to be bin Laden's safe harbor. Shortly after his arrival, the Taliban overran Nangarhar province and drove out Haji Abdul Qadir, the province's governor who had welcomed bin Laden. The governor fled to Pakistan, but bin Laden stayed.

The Taliban's control was reinforced by bin Laden's al-Qaeda group, which grew stronger with the support of Middle Eastern Muslims who had come to Afghanistan to fight the Soviets.

By the time Kabul fell to the Taliban in September 1996, the group's zone of control stretched from the border with Iran, through the country's south and into the eastern buffer area with Pakistan.

Immediately after capturing the capital, Taliban militiamen seized former President Najibullah from the city's U.N. compound, killed him, and hung his body from a traffic post in the city center.

But the fighting was still far from over, as Defense Minister Ahmed Shah Massood withdrew the ousted government's forces into the northern Panjshir Valley -- forming what is now known as the Northern Alliance. Warlord Abdul Rashid Dostum, who had fought alongside the Najibullah regime and now dominated the region around the northern town of Mazar-e-Sharif, also showed little interest in surrendering his powerful militia.

A seesaw battle was fought over the northern third of Afghanistan, until the Taliban finally overran Mazar-e-Sharif in August 1998, forcing Dostum and Rabbani to flee the country. Only 10 percent of the nation remained outside of Taliban control, mostly held by troops loyal to Massood.

Although hopes were raised in early 1998 that a broad-based religious commission could broker a peace agreement, the plan quickly fell apart and fighting resumed.

Since the Soviet Union's withdrawal from Afghanistan, an estimated one million people have died in the conflict -- with the Western world hardly taking notice.

But when terrorists hijacked four U.S. jetliners and crashed three of them into the World Trade Center and the Pentagon on September 11, the international spotlight again returned to Afghanistan.

This time, it was bin Laden's organization and the Taliban regime harboring al-Qaeda that were under the microscope. Bin Laden, already suspected as the ringleader in several terrorist acts against U.S. interests, was soon singled out as the suspected mastermind of the hijackings.

A few days after the attacks on America, a suicide bombers disguised as journalists killed the Northern Alliance's Massood.

But the alliance fights on, and has aggressively attacked the Taliban since the Sept. 11 attacks.