VATICAN CITY -- As he approaches the 25th anniversary of his papacy, Pope John Paul II is a picture of extreme fragility and sheer determination, of surprising resilience and severe physical limitations.
A hero to conservative Roman Catholics who see him as a fixed star shining on a world in moral flux, a disappointment to liberals who dared hope he would move the church their way, the pope is unquestionably among the most important religious figures of the last century.
Yet, in what even he calls his "twilight years," John Paul's reign has largely been about a painful, personal struggle with declining health while his legacy suffers from the effects of clergy sex abuse scandals, mainly in the United States and Europe.
It all makes for a bittersweet moment as the church prepares to mark the anniversary of John Paul's election on Oct. 16, 1978.
The Vatican has invited the entire College of Cardinals to Rome for nearly weeklong celebrations, along with the president of each national bishops' conference and a delegation of prelates from John Paul's native Poland. There will be an anniversary day Mass that is expected to attract tens of thousands of Romans to St. Peter's Square, a concert in his honor and a luncheon with all the cardinals.
The festivities continue with the Oct. 19 beatification of Mother Teresa of Calcutta - the tiny nun who devoted her life to the poor. John Paul was so impressed with her work that he put the nun, who died only six years ago, on the fast track to sainthood.
Events conclude two days later with the installation of 30 new cardinals, whose nomination last month was a sign of the pope's intent to influence the choice of a successor.
Indeed, there is much to celebrate. This is a pope who will be remembered for helping end communist rule in eastern Europe by sparking what amounted to a peaceful revolution in his homeland; for seeking to heal divisions between Christians and Jews; and for traveling around the globe to greet his 1-billion-member flock.
He has been a constant voice for peace. In 1984, he stepped in and mediated a territorial dispute between Chile and Argentina when the two mainly Catholic South American neighbors were on the brink of war.
John Paul was more successful there than in opposing both the 1991 Gulf War and the U.S.-led invasion of Iraq this year. Still, he has been persistent: In the aftermath of the Sept. 11, 2001, attacks, the pope has repeatedly denounced violence committed in the name of religion.
He also has tried to develop warmer relations with Jews, extending the Vatican's full diplomatic recognition to Israel, becoming the first pontiff to visit the main Rome synagogue, repeatedly denouncing anti-Semitism and issuing a statement of Christian contrition over the Holocaust.
"John Paul will go down in history as the most important world leader in the second half of the 20th century," said the Rev. Thomas Reese, editor of the Jesuit magazine America.
As a footnote to church history, John Paul's pontificate is closing in on the third-longest: Pope Leo XIII's reign about a century ago lasted 25 years and four months. The first pope, St. Peter, served as leader of the church for at least 34 years and is considered the longest-serving pontiff.
At 83, John Paul is a stooped figure, suffering since the mid-1990s from Parkinson's disease and crippling knee and hip ailments. The Vatican - adapting to his weakened condition - has devised a throne-like chair on wheels that allows him to celebrate Mass while seated.
Burdened by his age and his ailments, he has referred more and more to his own mortality. While visiting Poland last year - a trip many Poles feared would be his last to his homeland - John Paul made an unscheduled stop outside a Krakow church where he was pastor from 1948 to 1950 and asked for prayers "for the pope during his lifetime and after his death."
During birthday celebrations at the Vatican in May, he told his fellow Poles that "I am increasingly aware that the day is drawing near when I will have to present myself to God and make an accounting of my whole life."
Recent comments to a German weekly by papal adviser Cardinal Joseph Ratzinger that John Paul was "in a bad way" caused a tumult, and Austrian Cardinal Christoph Schoenborn only fueled speculation in a broadcast interview this month by saying the pope is approaching "the last days and months of his life."
Other church officials quickly moved to say that did not mean the pope's condition had worsened recently, nor that he had lost the ability to govern.
John Paul has repeatedly brushed aside any suggestion he step down, declaring he wants to continue his mission "until the end" and asking for prayers so he can "faithfully carry out the mission that the Lord has entrusted to me."
Still, some aides worry what may happen if the pope known for his skills as a communicator can no longer speak.
During a pilgrimage to Slovakia in mid-September - his 102nd foreign trip - he had such difficulty speaking that Slovak prelates read most of his speeches. A man known as an avid sportsman in his youth, who skied and hiked during the early years of his pontificate, had to be carried by aides from his limousine to a special lift used to board his plane.
The Vatican, long reluctant to acknowledge the Parkinson's disease, now cites John Paul as an example of how people can battle their physical weaknesses.
"It is very moving how he has incorporated the physical limitations into the way he performs his ministry," said John Paul's spokesman, Joaquin Navarro-Valls.
Pope Paul VI, stricken with arthritis, was virtually immobile in the waning years of his papacy. In one of his last public appearances before his death at 80 in 1978, he was borne aloft by aides on a chair and carried into the funeral of the assassinated Italian politician Aldo Moro.
Popes can resign - Pope Celestine V abdicated in 1294 - but church law contains no provision for removing an incapacitated pope.
John Paul, however, still has ambitions. His spokesman says the pope is finishing a book on his days as a bishop and still may accept invitations for visits next year to Austria, Switzerland and France as well as a return to his homeland.
"Parkinson's is quite variable, and people can function for quite a long time, meaning 10, 20 years with good treatment," said Dr. Cheryl Waters, professor of neurology at Columbia University in New York.
She said the pope looks more fragile than the average patient with the disease because of his age and other illnesses.
Parkinson's is a progressive neurological disorder, "and we can expect further difficulties in activities such as writing, speaking, walking and balance," she said.
Already, the pope has outlived many men once considered possible successors, and on Sept. 28 he announced the latest group of bishops that he'll elevate to cardinal, further putting his mark on the body that will elect his successor.
Even without this latest round of appointments, John Paul has named all but five of the 109 current cardinals - many of them like-minded conservatives. He's had a similar impact on the ranks of bishops around the world.
The pope had not been expected to name new cardinals until early next year, leading to questions about whether he moved up his decision because of his failing health.
John Paul was a vigorous man when elected as the first non-Italian pope in 455 years. A Turkish gunman shot him in the abdomen in a 1981 assassination attempt, but the pope soon resumed his full schedule - against the advice of his doctors, who pleaded that he cut back.
Even as he has finally slowed down, he has pursued an agenda that has angered liberals, including strong support for church law barring women from the priesthood and priests from marrying. Recently, he endorsed a worldwide campaign to keep same-sex unions from receiving legal recognition.
"There is a blatant contradiction between the foreign policy of this pope and his domestic policy," dissident theologian Hans Kung told The Associated Press.
"I find it remarkable how the pope spoke out for human rights, freedom and democracy and especially against the war in Iraq, and also for the dialogue of religions," he said. "But, on the other hand, he represses freedom in the Catholic Church, he supports the inquisition against reformist theologians and bishops. He holds intolerant positions on questions like birth control and abortion."
Beyond criticism from the left, this papacy has had its setbacks.
John Paul has often lamented that the countries of eastern Europe, freed from Soviet communism, have adopted the West's consumer culture while the writers of a proposed constitution for the European Union have refused to include a direct reference to the continent's Christian heritage.
Certainly, one of the pope's greatest sorrows has been the inability to achieve reconciliation with the Orthodox Church. Beyond theological differences over papal supremacy, relations with the Russian Orthodox Church have worsened since the fall of communism.
The Russians have expressed alarm over the Vatican's missionary advances in traditional Orthodox territory once communism-era persecution of Catholics ceased. Orthodox leaders have thwarted John Paul's desire to become the first pope to visit Russia.
"The greatest disappointment of his papacy must be that a liberated eastern Europe did not become a force for the spiritual renewal of the West, but rather the West with its individualism and consumerism has corrupted the East," Reese, the magazine editor, said.
Papal spokesman Navarro-Valls countered that it was most important that "the pope freed thousands - no millions - of people living under communist rule."
Revelations of priestly sex abuse and attempts by bishops to cover molestation charges have rocked the church for two years, mainly in the United States but in other countries as well, including John Paul's Poland.
The pope has spoken out several times, telling a worldwide meeting of young Catholics in Toronto last year that the "harm done by some priests and religious to the young and vulnerable fills us all with a deep sense of sadness and shame."
While criticized by victims as slow to acknowledge the problem, the Vatican did sign off last year on a toughened policy for dealing with clerical molesters in the United States.
When all is said and done, John Paul's supporters will argue that the pope's accomplishments far outweigh the problems of his reign, giving Catholics reason to take pride in his anniversary.
Said Navarro-Valls: "John Paul is a realist. He doesn't allow disappointments to get to him."
Key dates in John Paul II's papacy:
-Oct. 16, 1978: Cardinal Karol Wojtyla of Krakow, Poland, elected pope by cardinals, first Pole ever and first non-Italian in 455 years. Succeeds Pope John Paul I, who died after 34-day papacy.
-Jan. 25, 1979: First trip abroad, to Dominican Republic, Mexico, Bahamas.
-June 2, 1979: First trip back to Poland as pope.
-Sept. 29, 1979: Travels to Ireland and United States.
-May 13, 1981: Shot in abdomen by Turkish extremist in St. Peter's Square.
-April 13, 1986: Makes historic visit to Rome's main synagogue.
-Dec. 1, 1989: Meets with Mikhail Gorbachev at Vatican, first ever meeting between a pope and a Kremlin chief. Establishes diplomatic ties between Vatican and Russia.
-May 1, 1991: Issues first encyclical on social issues since fall of communism in Europe, giving qualified approval to capitalism but warning rich against exploiting poor.
-July 15, 1992: Operation for benign tumor on colon.
-Oct. 31, 1992: Formally declares church erred in condemning Galileo.
-Oct. 5, 1993: Issues encyclical "Splendor of Truth," major statement defending absolute morals against liberal theologians.
-Nov. 11, 1993: Dislocates right shoulder in fall down steps at Vatican event, requiring surgery.
-Dec. 30, 1993: Agreement signed establishing formal ties between Vatican and Israel.
-April 29, 1994: Breaks leg in fall and undergoes hip replacement surgery.
-Oct. 19, 1994: His book, "Beyond the Threshold of Hope," published.
-Oct. 8, 1996: Surgery to remove appendix.
-March 1, 1999: Vatican confirms pope has waived five-year waiting period and begun beatification process for Mother Teresa.
-March 20-26, 2000: Makes first trip to Holy Land and expresses sorrow for suffering of Jews at Christian hands in note left at Jerusalem's Western Wall.
-Sept. 11, 2001: Condemns "unspeakable horror" of Sept. 11 attacks.
-April 23, 2002: Meets with U.S. cardinals to discuss sex abuse scandal; says no place in priesthood for clerics who abuse young.
-Feb. 14, 2003: Receives Iraqi deputy prime minister Tariq Aziz on eve of war.
-June 5-9, 2003: Makes 100th foreign trip, visiting Croatia.
-July 31, 2003: Vatican launches global campaign against gay marriages.