Pope Benedict XVI travels to Turkey in late November, a four-day visit aimed at building bridges with Islam, reaffirming dialogue with Orthodox Christians and encouraging a tiny Catholic minority in a Muslim country.

The Nov. 28-Dec. 1 trip was first envisioned as an ecumenical event, but interreligious issues have taken center stage. The pope's remarks about Islam at the University of Regensburg in September upset many Muslims, and Turkey will offer the pope a platform to explain his views to the Islamic world.

It will be the pope's fifth visit outside Italy and his first to a country with a Muslim majority. He arrives in Ankara for meetings with government officials, goes to the historic site of Ephesus for Mass, and closes out his visit with Orthodox and Catholic communities in Istanbul.

Situated where Asia and Europe meet, Turkey has for centuries been a place where Islamic cultures met the "Christian" West --- often in conflict, as at the time of the Crusades. In the current climate of global cultural and religious tensions, that makes the papal visit all the more significant.

"It's an extremely important trip," said Father Justo Lacunza Balda, an official of the Pontifical Institute for Arabic and Islamic Studies in Rome.

"There are so many issues that touch Turkey, including dialogue with Muslims, cultural and religious identity, the future of Europe, church-state relations, religious freedom and ecumenism. The pope's visit is a sign of respect for the country and a sign that these issues need to be discussed," he said.

On several levels, the trip represents a test of Pope Benedict's 18-month-old pontificate. Vatican officials believe the results will hinge on answers to some key questions:

---Can the pope begin to heal the recent rift with Islam, while still engaging Muslims in honest dialogue on crucial issues --- including the question of faith and violence?

---Can the pope get a hearing from the Turkish population and government hosts when he speaks about the importance of religious freedom and human rights in a modern democracy?

---When he meets with Orthodox Ecumenical Patriarch Bartholomew of Constantinople, will the pope simply be keeping up a tradition, or can he use the encounter to generate ecumenical momentum and direction?

Pope Benedict knows how important this trip is, and he's showing it by taking along five top Vatican cardinals, including those responsible for interreligious and ecumenical dialogue.

The tone of the visit may become clear on the opening day, when the pope meets with government officials and diplomats in Ankara, the Turkish capital.

On his way into the city from the airport, the pope will make a brief but significant stop at the mausoleum of Kemal Ataturk, the founder of modern Turkey. The pope is expected to write a sentence or two in the guest book, and his words may offer a thematic clue to the visit --- especially on the issue of church-state relations.

At the Ankara State Guest House, the pope will be greeted by President Ahmet Necdet Sezer. The absence of Prime Minister Recep Tayyip Erdogan, who will be out of the country at a NATO summit, has been seen as a snub by many observers, but Vatican officials say the scheduling conflict was known for months.

One of the most interesting encounters of the first day will be the pope's meeting with Ali Bardakoglu, the head of Turkey's directorate of religious affairs. After the Regensburg speech, Bardakoglu sharply criticized the pope's remarks on Islam and said the pontiff should "rid himself of feelings of hate" and apologize. He later accepted the pope's expression of regret.

Both the pope and Bardakoglu will deliver speeches. Church officials hope it will be an opportunity for mending bridges and looking ahead, rather than a revival of the recent polemics. Bardakoglu, in fact, has said he doesn't intend to bring up the Regensburg speech unless the pope does.

At the Vatican, sources say they expect the pope to present a strongly positive message, communicating his respect for Muslim believers and his appreciation for the values of Turkish society and indicating common ground in the idea that civil society cannot exclude God.

On Nov. 29 the pope will say Mass at a Marian sanctuary near Ephesus, a center of early Christianity that St. Paul used as a missionary base. The shrine, called the House of the Virgin, is believed by some to be the place where Mary lived at the end of her life and is visited by some 3 million pilgrims each year --- most of them Muslims, according to church sources.

The pope lands in Istanbul later Nov. 29, and the focus of the visit turns ecumenical. He will attend a prayer service that evening at the headquarters of Patriarch Bartholomew and will return there for a major liturgy to mark the Nov. 30 feast of St. Andrew the Apostle, the patron saint of the patriarchate. The pope and patriarch will then sign a joint declaration on the continuing search for Christian unity.

Vatican and Orthodox officials don't want the ecumenical side of the Turkey trip to be overlooked.

"We are very unhappy with the fact that people are only talking about the interreligious aspect. The main purpose of the trip remains ecumenical, and we hope it will bring a new impetus and enthusiasm for dialogue with the Orthodox churches," said Cardinal Walter Kasper, the Vatican's top ecumenist.

The pope also will visit the heads of the Syrian Orthodox and Armenian Orthodox churches in Turkey and will meet privately with Turkey's chief rabbi in Istanbul.

In a visit that was rescheduled from a Friday to Thursday in order not to risk offending Muslims on their day of prayer, the pope will tour the Hagia Sophia Museum --- an architectural masterpiece that began as an Orthodox church, was transformed into a mosque in the 15th century and became a museum in 1935.

The pope's final day is dedicated to Turkey's tiny Catholic minority, estimated to number about 33,000 --- about .05 percent of the population.

He will say Mass in Istanbul's small Cathedral of the Holy Spirit; those who can't squeeze into the church can watch the liturgy on screens in the courtyard of the nearby Church of St. Anthony.

Throughout the visit, the pope is likely to highlight the church's deep roots in Turkey. Asia Minor was visited by apostles and was home to church fathers, and every ecumenical council during Christianity's first millennium was held on what is now Turkish territory.

At some point, the pope also is expected to remember the sacrifice of a modern evangelizer: Father Andrea Santoro, an Italian missionary who was shot and killed by a 16-year-old Muslim last February.

Both Orthodox and Catholic leaders hope the papal visit will boost their ongoing efforts for recognition of religious rights. Catholic officials, for example, have been pressing for legal recognition of the Latin-rite church, which has no juridical status in Turkey.

Turkey's Constitution protects freedom of conscience, but the country's brand of secularism controls all religious activity and keeps an especially tight rein on religious minorities.

Church leaders are hoping that Turkey's projected entry into the European Union will provide leverage for greater protection of their rights. But that could backfire; European pressure on human rights is thought to be one reason for a recent decline in support for EU entry among Turks.

If the pope does address the religious liberty issue, he may choose to cite Turkey's own Constitution, rather than ask the country to meet European standards.

---CNS