The Argentine pontiff flew into the central Portuguese town on board a helicopter, circling twice over a giant, 400,000-capacity, packed esplanade that faces the Sanctuary of Our Lady of Fatima to enthusiastic cheering.
Disembarking in a nearby stadium, he set off in his "Popemobile" for a journey through town followed closely by hovering helicopters, ending up at the sanctuary where pilgrims from all over the world had been waiting eagerly for hours.
"I implore for concord among all people," he then said in comments broadcast across the holy site.
Pilgrims from countries as varied as China, Venezuela and East Timor listened intently, some crying, the flags they had been waving enthusiastically just moments before standing motionless.
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"In the joy of the Gospel, we will be the Church robed in white, the whiteness washed in the blood of the Lamb, blood that today too is shed in the wars tearing our world apart," he added.
"We are going to pray to Fatima and Pope Francis so that they can intervene for a peaceful solution for Venezuela," said Jose Ornelas, a 59-year-old librarian who came all the way from Caracas, which along with other cities has been wracked by deadly anti-regime protests.
"We are living in a violent spiral with so much hate and so much helplessness."
Fatima has become a major holy site since the Virgin is said to have appeared in 1917 to Jacinta, 7, Francisco, 9, and their cousin Lucia, 10.
These reportedly included a warning of a second war.
On Saturday -- the 100th anniversary of the first reported apparition -- Pope Francis will canonise Jacinta and Francisco, who have officially been credited with two miracles.
Many pilgrims trekked to Fatima for days on foot -- some finishing the last few metres on their knees.
Others staked out a prime spot next to the railings marking off the route where Pope Francis rode his "Popemobile."
"We came and went. We stood guard just like soldiers," she joked.
And while the atmosphere was one of joy, emotions ran high and difficult memories bubbled to the surface.
Dung Lu, a refugee from Vietnam living in Denmark, said she and her mother fled their country in the late 1980s, partly because they were unable to practise their religion under the communist regime.
With tears in her eyes, she remembered praying to the Virgin Mary when she was still in Vietnam and her father was jailed after the war and then fled the country, leaving them behind. They were later reunited.
"It's difficult to tell them how hard it was. They (were) born in freedom," she said.
Pope Francis is the fourth pontiff to make a pilgrimage to Fatima in half a century.
Arguably the most devoted was the late Pope John Paul II, who attributed his narrow escape from an assassination attempt at St. Peter's Square on May 13, 1981 -- the anniversary of the first reported apparition -- to the intervention of the Virgin Mary.