Since becoming pope two decades ago, John Paul II has sought to reconcile the deep rifts between the Roman Catholic and Eastern Orthodox churches.
This past weekend he moved one step closer to that goal.
The pontiff's historic three-day visit to Romania was the first time a pope has traveled to a majority Orthodox country in nearly 1,000 years and is expected to improve relations between the estranged churches.
The pope was warmly greeted at the airport by Patriarch Teoctist, leader of the Romanian Orthodox Church.
They then traveled side by side in the bullet-proof "popemobile" to an Orthodox cathedral where they held a joint prayer service.
"The second millennium started with a painful division of the church, but it is ending with a sign of the will and efforts aimed at its reunification," Teoctist said.
They also issued a joint appeal for an end to the fighting in neighboring Yugoslavia, calling on all sides to lay down their arms. Both religious leaders have been critical of the NATO bombing campaign against Serbia, a predominantly Orthodox country.
While the appeal is unlikely to have an effect on the war, it is of symbolic importance for relations between the churches, which have been marked by suspicion and mistrust.
The Great Schism
No pope had visited a predominantly Orthodox country since the Great Schism of 1054 when the Eastern Orthodox Church broke with the Western (or Roman Catholic) Church following centuries of disputes. The pope and the patriarch of Constantinople excommunicated one another during the schism, acts that weren't mutually abolished until 1965.
Relations remained extremely poor until the early part of this century, owing in large part to successful papal efforts to convert Orthodox worshipers in Eastern Europe and the Balkans.
One result of this is the presence of tens of thousands of Eastern-rite Catholics in Romania, Ukraine, and other countries, who follow Orthodox rituals but recognize the authority of the pope.
This remains a major obstacle between the churches.
Since World War I, successive popes have worked to reconcile the churches. When he became pope two decades ago, John Paul II had hoped to achieve substantial reconciliation before the end of the millennium, but he has been rebuffed by Orthodox leaders suspicious of the Vatican's intentions.
"The pope believes that if there is to be true spiritual renewal of the Catholic Church it is going to come from the East, not the West," says Richard McBrien, professor of theology at the University of Notre Dame in Indiana.
"He has always had a very skeptical view of Western values and an innate preference for [Eastern Orthodoxy's] more mystical, spiritual, and formalized practices," Professor McBrien says.
"He's willing to do almost anything for this reconciliation," McBrien adds. "But the Orthodox are very skeptical of Rome's intentions."
A well-placed Orthodox Church official in the Balkans says the status of the Eastern-rite Catholic churches remains the major obstacle to further dialogue. "The Roman Church 'stole sheep' from the Orthodox in the 17th century," the source says. "That has caused tensions to this day."
Nudge from government
The pope's historic visit might not have come about without the active support of Romanian President Emil Constantinescu, a pro-Western intellectual who advocates Romania's integration with Western institutions, including NATO and the European Union. A presidential press officer in Bucharest says Mr. Constantinescu "played the main role in convincing the patriarch to issue the invitation."
Even so, Teoctist's invitation came with strings attached. The pope had to abandon plans to visit Transylvania and northwestern Romania, where most of the country's Roman and Eastern-rite Catholics live. He remained in the capital, Bucharest, for his entire visit. There he held a Catholic mass and visited the graves of an Eastern-rite bishop and cardinal imprisoned during the communist regime.
Nor does the trip necessarily open the way for the pope to visit Moscow, seat of the Russian patriarch, whose domain encompasses roughly half of the world's estimated 250 million Orthodox faithful. Relations are cool between Teoctist and his Russian counterpart, Patriarch Alexy II, because of a dispute over churches in Moldova.
Still, the visit set an important precedent. "It breaks the ice big time," says the Rev. Ronald Roberson, associate director for ecumenical affairs at the National Conference of Catholic Bishops in Washington.
"In that sense I'd say it was a smashing success."