Ayatollah Ruhollah Khomeini, 89, the Unwavering Iranian Spiritual Leader

The life of Ayatollah Ruhollah Khomeini was so shadowy, so overlain with myth and rumor, that there was lingering disagreement or uncertainty about his ancestry, his true name and his date of birth.

But when he returned in triumph to Teheran on Feb. 1, 1979 - after almost 15 years in exile - the imposing man in a black robe with a white beard and intense dark eyes left little doubt about who he was, or what he wanted for his ancient land.

Ayatollah Khomeini felt a holy mission to rid Iran of what he saw as Western corruption and degeneracy and to return the country, under an Islamic theocracy, to religious purity.

The Islamic Shiite leader's fervor helped drive Shah Mohammed Riza Pahlevi from the Peacock Throne on Jan. 15, 1979, and into foreign exile. The Shah's eventual arrival in the United States for cancer treatment was the spark that set off the American hostage crisis. Hostility for the West

Under the Ayatollah, Iran was wrenched backward from widespread economic development and social change and onto a path that was broadly hostile to the Western world.

The Ayatollah's path also led to eight years of bloody, costly, inconclusive war between Iran and its Arab neighbor Iraq. He demanded that his country fight unrelentingly after Iraq invaded Iran in September 1980, but he eventually accepted a truce in 1988.

Many longtime Iranian opponents of the Shah hoped that the Ayatollah would turn over power and allow a democratic society to emerge. But he held to his dream of an Islamic republic and retained his Islamic fervor -scuttling a tentative economic and political opening to the West in with his call for the killing of a British author, Salman Rushdie, whose novel ''The Satanic Verses'' was deemed to have blasphemed the faith.

A month later, he dismissed Ayatollah Hussein Ali Montazeri, a relative moderate who had been designated as his political heir. There has been speculation that Ayatollah Khomeini's son, Hojatolislam Ahmad Khomeini, is emerging from a power struggle as a prime contender to inherit his authority. A Leader Beyond Challenge There was no one in Iran with sufficient authority to challenge the Ayatollah successfully. In the aftermath of the revolution, he moved relentlessly toward his theocratic goal, consolidating power and silencing the opposition.

In a frenzy of political retribution and Islamic purification, thousands of people were executed in public, including the Shah's officials, torturers, criminals, homosexuals and prostitutes.

A 1987 report of the United Nations Commission on Human Rights estimated that as many as 7,000 people were shot, hanged, stoned or burned to death after the 1979 revolution. Executions continued over the years, the report said, but declined in number.

In 1979, a year of intense militancy, the leadership feared an American-inspired countercoup to restore the Shah, as happened in the early 1950's after Iran, under the nationalist grip of Prime Minister Mohammed Mossadegh, seized the Anglo-Iranian Oil Company in a royalties dispute and caused fright in Britain and the United States. U.S. Feared Soviet Inroads

In 1953, Washington was fearful of a Communist takeover and expansion of Soviet influence in the strategic region. It put the Central Intelligence Agency to work to undermine Dr. Mossadegh and to restore the Shah's power. The plot succeeded and the C.I.A. and its Teheran operatives prided themselves on it, wrote about it and talked about it for decades as a model of strategic conspiracy.

Twenty-six years later, in 1979, the Shah was again out of power and abroad, and again the United States played a central role in the turmoil as the new leaders insisted that the Shah be returned to Iran to stand trial for corruption and abuse of power.

Amid this dangerous mood of militancy, President Jimmy Carter overruled diplomatic advisers and intervened to allow the Shah to enter the United States for cancer treatment. In a fury, Iranians clambered over the walls of the American Embassy in Teheran on Nov. 4, 1979, seizing diplomats, staff members and military personnel as hostages to trade in exchange for the Shah.

The hostage crisis caused agony, fear and humiliation in the United States. There was well-founded dread that the captors, mostly student militants, might start shooting hostages to dramatize their demand for the Shah.

Under growing pressure in an election year, President Carter endorsed a desperate military rescue mission in April. The mission was abandoned at a desert site southeast of Teheran after three of eight helicopters had problems, leaving too few for a safe operation. As the rescuers rushed to get away before dawn, a helicopter crashed into a C-130 transport and exploded. Eight men died in the fire.

For the Ayatollah and most Iranians, the collapse of the rescue mission was cause for jubilation. Crowds celebrated in the streets. But for Mr. Carter, as he conceded later, it was the ignominious beginning of the end for his Presidency.

It was not until Jan. 20, 1981, Inauguration Day for Ronald Reagan, that the hostages were released, after 444 days. They flew out of Iran's airspace at almost the very moment that Ronald Reagan was taking the oath of office.

The seizure of the hostages was an assertion of defiance that had rallied Iranians behind the Ayatollah and helped insure approval of his new Constitution establishing Iran as an Islamic republic.

Lifelong supreme authority was vested in the Ayatollah, with the title Velayat Faghi, or Religious Leader. Wide Dissent in the Land

Despite approval of the Islamic republic by an overwhelming majority, there was opposition to the Ayatollah among liberals, rival religious leaders and many of Iran's ethnic minorities.

During the crisis over Americans being held hostage in Teheran, a renegade in Saudi Arabia, proclaiming himself the Mahdi, or Messiah, seized the venerated Grand Mosque in Mecca with a band of armed followers.

Within hours, the Ayatollah's office accused the United States and ''Zionists'' in the deed. Outraged Muslims in Islamabad, Pakistan, stormed and burned the United States Embassy. The Ayatollah sought to use the emotional issue to rally all Islam against the United States.

''This is not a struggle between the United States and Iran,'' he declared. ''This is a struggle between Islam and blasphemy.'' He talked again and again in such acerbic tones about the United States, the ''Great Satan.''

The Iranian regime's hatred for the United States played itself out many times in the Ayatollah's years. On July 31, 1987, thousands of chanting Iranian pilgrims in the holy city of Mecca, in Saudi Arabia, rampaged and fought with the Saudi Arabian riot police. Many were killed and wounded. ''Death to America! Death to France! Death to Israel!'' they shouted.

Again, the Ayatollah's regime accused the United States of having plotted the violence. Deep Divisions Over the U.S.

But there were occasional reports of differences in Iran on the issue of relations with the United States, and these hints of emerging ''moderation'' in Iran led to the greatest foreign-policy debacle of the Reagan years: the Iran-contra afffair.

Some Americans in the Reagan White House spoke of ''moderates'' in Teheran who looked to a time when the Ayatollah would pass from the scene. It was to such ''moderates'' that the White House turned in 1985, seeking influence to win the release of Americans being held in Lebanon by Islamic Shiite fundamentalist terrorists.

Complex deals of arms for hostages were played out, with disastrous results. The deals led to an uproar in Washington and across the country when it was discovered that the United States had traded arms to Iran in exchange for the release of American held captive in Lebanon.

In a troubling twist that was ultimately deemed illegal, the profits from the sales of American arms to Iran -mostly missiles that Iran used to in its long and bloody war with Iraq - went to support the Nicaraguan guerrillas.

In the fall of 1986, Ayatollah Khomeini criticized Iranians who had taken part in the dealings with Washington, calling them ''Satan-oriented.''

''I never expected such things from such people,'' he said. Iran retreated even further from the West. Conflicting Birthdates

The man who became the Islamic ruler of Iran and a force in much of the world was born, by varying accounts, in 1900, 1901 or 1902. Iranian accounts put his age at 86, but May 27, 1900, has become the most accepted date for the Ayatollah's birth, making him 89 at the time of his death. His birthplace was the town of Khomein, about 180 miles south of Teheran. His father was a mullah, or religious leader.

Little is known of the Ayatollah's childhood except for one event that possibly influenced his character. When he was an infant, his father was murdered, apparently in a dispute with a landowner over irrigation rights.

The Ayatollah's supporters have asserted that his father was killed on orders of Riza Khan, the officer who seized power in 1921, assumed the throne as Riza Shah in 1925, took the dynastic name Pahlevi and changed the name of Persia to Iran, for its prehistoric Aryan roots.

But a flaw in the account was the fact that the murder of the Ayatollah's father had occurred two decades before Riza Khan's coup. Studies Theology And Takes a Bride Raised by his strong-willed mother and aunt, the Ayatollah began religious studies in Khomein. According to various accounts, he continued his studies at the Marvi Theological School in Teheran, in the Shiite shrine city of Najaf in Iraq and in Isfahan and Arak.

In the 1920's, Ayatollah Khomeini followed his tutor to Qum, where he completed his studies, worked as a teacher and became interested in Islamic mysticism and Plato's ''Republic,'' which may have helped shape his vision of an Islamic state led by a philosopher-king.

It was during these years that the Ayatollah married, reportedly a woman from Qum. They had a daughter who died in infancy and a son, Mustafa, whose death in the 1970's provoked speculation that he had been killed by the Shah's secret police.

According to some accounts, the Ayatollah's first wife died and he then married the daughter of a wealthy landowner. They had, it was said, three daughters and a son, Ahmad, who went on to serve as his father's chief aide. Dissent Stirred in 1941

The Ayatollah apparently concentrated on theology through most of Riza Shah's reign, for there are no accounts of opposition activity until 1941, the year that the old Shah, pro-German and anti-British, was deposed by British forces in favor of his son, Mohammed Riza. The Ayatollah was unequivocal when he did speak out, in a book called, ''Unveiling the Mysteries.''

''The orders of the dictatorial state of Riza Shah,'' he declared, ''are valueless and all laws approved by the Parliament must be burned.''

The book, foreshadowing the Ayatollah's later campaign, accused Riza Shah of persecuting the clergy, destroying Islamic culture and submitting to foreign domination. It also had the first known outline of the Ayatollah's Islamic state, which he came to regard with increasing fervor as the only legitimate form of government.

''God,'' he wrote, ''has formed the Islamic Republic. Obey God and his Prophet and those among you who have authority. It is the only government accepted by God on Resurrection Day. We don't say that the Government must be composed by the clergy but that the Government must be directed and organized according to the divine law, and this is only possible with the supervision of the clergy.'' Polemics Attracted the Young

The book created an uproar. Students applauded it but the older, more conservative mullahs were uneasy.

Although he continued to speak out and was gaining a zealous following, the Ayatollah's campaign was overshadowed in 1951 when the National Front Government of Dr. Mossadegh came to power and when, in 1953, the Shah was briefly driven into exile. The Ayatollah sympathized with the opposition to the Shah but he regarded the Mossadegh Government as too secular and yearned for an Islamic state.

It was in the years after the Shah was restored to the throne by the C.I.A. that Ruhollah Khomeini acquired the honorific Ayatollah, or Reflection of Allah, a title that is bestowed by acclamation of a mullah's followers. It is held by more than a thousand mullahs in the Shiite world.

By the time he took the lead in the opposition to the Shah, he had received the title of Grand Ayatollah, held by only six other mullahs in Iran at the time. That was 1962, when the Ayatollah led a general strike against a ruling that witnesses in court no longer had to swear by the Koran. Opposed the Shah's Modern Society In 1963, the Shah announced his White Revolution to modernize Iran swiftly and from top to bottom, a program that included emancipation of women and seizure of the vast lands controlled by the clergy. The Ayatollah spoke out forcefully against it.

He won support from the students at Teheran University, who distributed as many as 200,000 copies of his statements, marking the first link between the religious leader and young intellectuals opposed to the Shah.

In June, when the Ayatollah, preaching to 100,000 at a Qum mosque, demanded that the army depose the Shah, he was arrested. Riots followed.

Released from jail, he was kept under house arrest for almost a year and then detained again in November 1964 when he vehemently protested an agreement exempting American servicemen in Iran from the jurisdiction of the country's courts.

When he was brought before Prime Minister Hassan Ali Mansour and refused a last-minute appeal to drop his opposition to the Government, the Prime Minister reportedly slapped him and ordered him into exile.

Weeks later, Prime Minister Mansour was assassinated by a young gunman carrying the Ayatollah's picture. A Relentless Campaign

The Ayatollah went first to Turkey but then moved his base to Iraq, settling in Najaf and continuing his relentless campaign against the Shah.

Because of the Shah's control of Iranian politics and such institutions as the press, it was to the mullahs, with their traditional role as champions of the downtrodden, that the discontented turned for leadership.

As an exile in neighboring Iraq with more freedom to speak out than people at home, Ayatollah Khomeini provided the polemics and inspiration.

The Shah, backed by the army and the country's oil wealth, ignored the constant denunciations, but as the Ayatollah's influence grew - fed by growing disenchantment with corruption, repression and the cultural upheavals of modernization - the Government grew ever more concerned.

In January 1978, an article mildly critical of the Ayatollah was planted in a Teheran newspaper and proved an immediate, and costly, mistake.

In response, demonstrators carrying pictures of the Ayatollah poured into the streets of virtually every city and town in the country. The yearlong battle for Iran was on. By September the revolt had spread to the oilfields, where workers began a crippling strike, leading the Shah to declare martial law. For the Shah, It Was Too Late The next month, Iraq, reportedly acting at the request of Iran, stationed policemen around Ayatollah Khomeini's house, provoking more demonstrations. The Shah, finally recognizing the Ayatollah's influence, switched tactics and proclaimed an amnesty that would have let him and thousands of other exiles to return home. It was too late. The Ayatollah refused, saying he would not return until the Shah was gone.

When the Ayatollah was expelled from Iraq he moved to France and set up headquarters in the Paris suburb of Neauphle-le-Chateau. There, he and his aides coordinated the activities of hundreds of mullahs in Iran by telephone.

In the frantic days of December 1978, the Ayatollah refused offers of compromise, insisting on the Shah's ouster.

When the Shah left Iran on Jan. 16, the Ayatollah denounced the new Government that the Shah had appointed. Attempts to Thwart Return

Caught between the Ayatollah's intransigence and a powerful army still loyal to the Shah, Prime Minister Shahpur Bakhtiar first closed Teheran airport to thwart the Ayatollah's return, then relented.

Finally, on Feb. 1, Ayatollah Khomeini flew home, reclining on a carpet on the floor of an Air France plane.

Within days, the Bakhtiar Government had faded away and the Ayatollah was in full control.

He told the Iranians, ''The remaining one or two years of my life I will devote to you to keep this movement alive.''

Insisting at first that he would defer to the provisional secular Government he established, the Ayatollah went to Qum but was soon undercutting his own ministers at virtually every turn, ridiculing the Prime Minister, Mehdi Bazargan, as weak and ruling increasingly through a secret, mullah-dominated Islamic Revolutionary Council and similar bodies.

To the dismay of the National Front and other secular groups that had helped lead the struggle against the Shah and hoped to establish a modern democracy, the Ayatollah moved to impose Islamic rule. Orders Women To Wear Veils He ordered women to wear the modest chador, a full-length gown, and veil, he allowed no criticism of his rule and when his Oil Minister resisted demands for a purge of non-Islamic workers among the industry's 40,000 employees, he dismissed him as a traitor.

Asked by the Italian journalist Oriana Fallaci in 1979 about reports of executions of homosexuals, prostitutes and adulterers, the Ayatollah said: ''If our finger suffers from gangrene, what do you do? Do you let the whole hand, and then the body, become filled with gangrene, or do you cut the finger off?''

The Ayatollah described music as ''no different from opium'' and banned it from television and radio. Music, he said, ''stupefies persons listening to it and makes their brain inactive and frivolous.''

Because of Iran's increasing isolation in the Khomeini era, it was often difficult to assess the precise role of the Ayatollah in ruling the country. But his influence as interpreter of the divine will and symbol of the Islamic Republic was strong and durable. In the years after his rise to power, his Government endured an ineffective Western arms embargo, rebellion by Kurdish and Baluchi minorities and a wave of assassinations in 1981 when the Marxist Mujahedeen turned against him. Backing to Terrorists

After 1980, the the Government began financing and supporting local rebel groups in Persian Gulf countries, including Kuwait, Bahrain and Saudi Arabia, and according to the United States, gave backing to terrorist bombings and hostage taking.

The Ayatollah's hopes that his revolution would spread were not fulfilled. But as the Baghdad-born University of London scholar Elie Kedourie wrote in May 1989 in the Times Literary Supplement - a British weekly - an abiding goal of the Iranian Islamic Republic is ''to liberate the disinherited masses of the Muslim world, whether these live in independent states like Egypt or Saudia Arabia or Morocco or the Emirates of the Gulf, or whether they are under non-Muslim rule, as in the Soviet Union or Israel.''

Understandably, not a few Western analysts of the Middle East came to believe that the Ayatollah's Iran was inflexibly bent on expanding its brand of revolutionary fundamentalism across the Arab world - and were then surprised at how easily Iran adjusted to the truce in the Gulf War. A War Without Victory or Defeat That the Ayatollah's regime managed to survive that gruelling conflict was a striking success of sorts. After the initial Iraqi invasion, as the Iranian Army, with the help of Revolutionary Guards, volunteer suicide squads and masses of young conscripts, retook land with human wave attacks, and then lost it again, the Ayatollah's Government used the nationalist fervor to consolidate its rule. The war was fought to a bloody stalemate.

Casualties on both sides were immense and the financial cost enormous. The war threatened a new international oil crisis as attacks increased on tankers in the gulf. In July 1987, the United States put naval forces in the gulf to escort Kuwaiti tankers.

Despite the suffering and cost, Ayatollah Khomeini urged his people to fight on until victory over Iraq. Speaking in February 1987, he called the war a ''divine cause.''

''Almost every day, Iran is hit and many children, youngsters, old men and ordinary people see their homes fall in on them,'' he said. ''But as soon as they clamber from the rubble they speak of the need for us to make war until victory.'' But in the months that followed, it became more and more evident that Iran's larger army would not bring it victory over Iraq, which remained largely on the defensive but controlled the air with its warplanes and sometimes made telling use of missiles and even poison gas. Peace a 'Deadly Poison'

It was on a note of Islamic fatalism that the Ayatollah finally, in July, 1988, announced his acceptance of the truce. ''I had promised to fight to the last drop of my blood and to my last breath,'' he noted in a statement reported by the Teheran radio.

''Taking this decision was more deadly than taking poison,'' he went on, ''I submitted myself to God's will and drank this drink for his satisfaction.''

With the hostilities ended, there followed an upsurge in political crosscurrents and bickering in Iran. Ayatollah Khomeini's ouster of Ayatollah Montazeri as his successor-designate in March, 1989. came after that cleric suggested that the Iranian revolution was off course: in radio and television messages he had criticized aspects of the regime, including its its view that those who did not unquestioningly support it were foes of Islam. In the months that followed, Ayatollah Khomeini's son Ahmad came to be seen, amid a welter of rivalries, as a chief candidate to assume his father's leadership role. No new heir was formally named.