A plane carrying Pope Benedict XVI has arrived at Beirut's Rafik Hariri airport, witnesses said, at the start of a three-day visit aimed at addressing the position of Christians in a region torn by civil war in neighbouring Syria.
The Lebanese deployed thousands of troops on Friday to secure the pope's visit in which he is expected to stress unity
among the different Christian churches in the Middle East and peace between Christians and Muslims.
Religious pluralism and the welfare of Christians in the region were likely to top the agenda of his tour, but the pontiff was also expected to call for an end to the conflict in Syria and a halt to arming the two sides.
He will call on Lebanon's Christians to unite, divided as they are not only toward the regime of Syrian President Bashar al-Assad, but also on a political vision for their own country.
But the Vatican has said the pontiff will avoid intervening politically in his comments on Syria or tell Christians where their alliances should lie.
Benedict, 85, faces a packed schedule in the majority-Muslim country, which will take him from the presidential palace in the Mediterranean seaside capital of Beirut to important Christian towns in the nearby mountains.
He will reach out to the 13 million or more Catholics in Lebanon and the Middle East, asking them to work for peace and democracy alongside moderate Islamists, in a period fraught with fears of a rise of fundamentalism.
Those concerns are particularly poignant as the region is rocked by deadly violence over a video mocking Islam that has cost the lives of the US ambassador in Libya including four other Americans.
Around 200 protesters took to the streets of the northern Lebanese city of Tripoli on Thursday to express outrage over video purportedly made in the US.
The pope hopes to advance the church's sometimes difficult relationship with Islam. While in Lebanon, he will meet not only local Christian leaders but Muslim ones as well.
His choice of Lebanon for his Middle East trip is not a casual one: the multi-confessional society - in which top political posts are split among religious groups - was hailed by pope John Paul II as a model for the region.
As the balance of power continues to shift in the region and with Christian minorities increasingly agitated, the emphasis will be on religious pluralism.
Benedict will weigh his words carefully to avoid politically charged comments that could increase religious tensions - and is expected to speak out in favour of a secularism that guarantees cultural and religious freedom.
He will also tackle concern over the exodus of Christians from the region during a presentation of results from the 2010 synod with Middle East bishops.
He has already received a request to recognise the Palestinian state and the important role of the Palestinian cause in the Arab world.
And Syriac Patriarch Ignatius Joseph III Younan has said he hopes the pope will also use the trip to call for negotiations in Syria.
Here too Benedict must tread carefully. The political class in Lebanon - including people from the Maronite church, Lebanon's largest - are divided, some supporting the Assad regime and others backing the rebels.
On Thursday, Maronite Patriarch Bishara Rai said "the pope will definitely call for an end to the spiral of violence and to hatred, which are pointless, and for those who finance and arm both sides in the conflict to stop doing so".
In the run-up to the pope's visit, Lebanese security forces are on high alert, and Interior Minister Marwan Charbel said this week that it "will be one of the most successful visits in the history of modern Lebanon".
The pontiff will arrive at Beirut's Rafiq Hariri International Airport early in the afternoon to a 21-gun salute. After his welcoming ceremony, he will travel to Harissa in the mountains northeast of the capital, where he will be staying.
While there, he will sign the final report on a synod of bishops he convened two years ago to study the future of Christians in the Middle East.
On Saturday, he will meet President Michel Sleiman, a Maronite, and Prime Minister Najib Mikati, a Sunni, as well as Muslim religious leaders and the diplomatic corps in Beirut.
He also expected to meet eastern patriarchs and bishops in Bzommar over lunch, to be followed by a meeting with Lebanese youth at the Maronite patriarchate in Bkerke, another village in the same area.
On Sunday, he will celebrate an open-air mass at the Beirut City Centre Waterfront and unveil the conclusions of the 2010 synod of bishops. He returns to Rome on Sunday evening.