Benedict flew by helicopter to the Adriatic port of Bari, considered a "bridge" between East and West that is home to the relics of St. Nicholas of Myra, a 4th-century saint who is one of the most popular in both the Roman Catholic and Orthodox churches.
The trip was Benedict's first outside Rome since being elected the 265th leader of the Roman Catholic Church on April 19 and, though brief, showed he was following in the much-traveled footsteps of his predecessor, Pope John Paul II. After the 3 1-2 hour visit, he departed by helicopter for the Vatican.
Benedict referred to Bari as a "land of meeting and dialogue" with the Orthodox in his homily at a Mass that closed a national religious conference.
"I want to repeat my willingness to assume as a fundamental commitment working to reconstitute the full and visible unity of all the followers of Christ, with all my energy," he said to applause from the estimated 200,000 people at the Mass.
Words aren't enough, he said, adding that "concrete gestures" were needed even from ordinary Catholics to reach out toward the Orthodox.
"I also ask all of you to decisively take the path of spiritual ecumenism, which in prayer will open the door to the Holy Spirit who alone can create unity," he said.
Benedict has said previously that reaching out to the Orthodox and other Christians would be a priority of his papacy, and his call to ordinary Catholics to take the charge as well built on that agenda.
The most-traveled pope in history, John Paul made 104 foreign pilgrimages and 146 pastoral visits in Italy during his 26-year papacy. John Paul visited Bari in 1984.
Benedict, 78, has said he is looking forward to attending the World Youth Day celebrations in Cologne, in his native Germany, this August — a trip John Paul had hoped to make himself.