Pope Francis returns to his father’s birthplace in northern Italy on Saturday for the first time since ascending the papacy to celebrate the 90th birthday of a second cousin who long knew him as simply “Giorgio.”

The visit to Francis' ancestral homeland to renew ties with family touches on keystones of Francis’ papacy, including the importance of honoring the elderly and the human toll of migration. Francis' private visit Saturday will be followed by public one Sunday to celebrate Mass for the local faithful, where he could well reflect on his family's own experience migrating to Argentina.

The pope's father, Mario Jose Francisco Bergoglio, and his paternal grandparents arrived in Buenos Aires on Jan. 25, 1929 to reach other relatives at the tail end of a mass decades-long emigration from Italy that the pope has honored with two recent saints: St. Giovanni Batista Scalabrini and St. Artedime Zatti.

The future pope, Jorge Mario Bergoglio, was born nearly eight years later in Buenos Aires, after the elder Bergoglio met and married Regina Maria Sivori, whose family was also of Italian immigrant stock, hailing from the Liguria region. Francis grew up speaking the Piedmont dialect of his paternal grandmother Rosa, who cared for him most days.

The elder Bergoglio was born in the town of Portacomaro, 10 kilometers (six miles) east of Asti, an agricultural town that lost population not only to emigration abroad but also to nearby Turin as it became an industrial center. Today, the town has 2,000 residents, but it numbered more than 2,700 a century ago, and dropped as low as 1,680 in the 1980s.

The pope’s family emigrated after the peak, which saw 14 million Italians leave from 1876 to 1915 -- a movement that made Italy the biggest voluntary diaspora in the world, according to Lauren Braun-Strumfels, an associate professor of history at Cedar Crest College in Allentown, Pennsylvania.

Often citing his own family story, Francis has made the welcoming and integration of migrants a hallmark of his papacy, often facing criticism as Europe in general, and Italy in particular, are consumed with the debate over how to manage today's migrations.

The pope has recognized the historic significance of the emigrant experience with the recent canonizations of St. Giovanni Battista Scalabrini, an Italian bishop who founded an order to help Italian emigrants at the end of the 19th century, and Artemide Zatti, an Italian who emigrated to Argentina in the same period and dedicated his work to helping the sick. He again used the occasion to denounce Europe’s indifference toward migrants risking their lives to cross the Mediterranean Sea for a better life.

Francis is to have lunch in the home of a cousin, Carla Rabezzana, who has told local media that she and the pope kept up their connections over the years.

“We have known each other forever,’’ Rabezzana told the Corriere della Sera newspaper. “When I lived in Turin, Giorgio -- I always called him that -- came to stay because I had an extra room. That is how we maintained our relationship.

“We always would joke. When he told me would come to celebrate my 90th birthday, I said it made my heart race. And in response I was told: ‘Try not to die.’ We burst out laughing.’’

The pope has many more third and fourth cousins still in the area.

“It was a large family, and in the area there are still many distant cousins,’’ said Carlo Cerrato a former mayor of Portacomoro. He said it was a “big surprise” for everyone in the town when Francis was elected pope nearly a decade ago.

“Everyone knew there was a prelate who had become the cardinal of Buenos Aires, but it was something that the relatives knew, not everyone in town,’’ Cerrato said.

While Francis is returning to the family's ancestral homestead in northern Italy, he has yet to return to his own birthplace in Argentina after nearly 10 years as pope. Francis, 85, hasn't really explained his reasons for staying away, but he recently confirmed that if he were to resign as pope, he wouldn't go back to Buenos Aires to live but would remain in Rome.