CASTEL GANDOLFO, Italy — Crowds gathered in the central square of this hill town south of Rome to catch a glimpse of history: Two Popes meeting for lunch and presumably discussing the future of the Catholic Church together.

Pope Francis flew in to the papal residence at Castel Gandolfo in the Alban Hills by helicopter Saturday where Pope Benedict XVI has been living since he resigned Feb. 28, the first Pope to step down in 600 years.

Benedict's dramatic departure that day — flying by helicopter from the helipad in the Vatican gardens with his weeping secretary by his side and circling St. Peter's Square in a final goodbye — is one of the most evocative images of this remarkable papal transition.

The Vatican is downplaying the luncheon in keeping with Benedict's desire to remain "hidden from the world" and not interfere with his successor's papacy. There was to be no live coverage of the private meeting by Vatican television, only a few still photos from the official Vatican photographer and perhaps a video released after the fact.

That didn't stop crowds from gathering outside the villa, even though at most it appeared all they might see is Francis' helicopter overhead.

The Vatican said Benedict would be at the helipad in the villa gardens to welcome Francis, and that the two would meet in Benedict's library and then lunch together. Francis will then return to his makeshift home at the Vatican hotel at an unspecified time later in the day.

The Vatican spokesman promised a general comment about the meeting, but no detailed statement.

All of which has led to enormous speculation about what these two men in white might have to say to one another after making history together: Benedict's resignation paved the way for the first Pope from Latin America, the first Jesuit, and the first to call himself Francis after the 13th century friar who devoted himself to the poor, nature and working for peace.

Perhaps over their primo, or pasta course during Saturday's lunch, the two popes might discuss the big issues facing the church: the rise of secularism in the world, the drop in priestly vocations in Europe, the competition that the Catholic Church faces in Latin America and Africa from evangelical Pentecostal movements.

Or maybe during their secondo, or second course of meat or fish, they'll discuss more pressing issues concerning Francis' new job: Benedict left a host of unfinished business on Francis' plate, including the outcome of a top-secret investigation into the leaks of papal documents last year. Francis might want to sound Benedict out on his ideas for management changes in the Holy See administration, a priority given the complete dysfunctional government he has inherited.

Then over coffee, they might discuss the future of Monsignor Georg Gaenswein, Benedict's trusted aide who has had the difficult task of escorting his old pope into retirement and then returning to the Vatican to serve his successor in the initial rites of the office.

Gaenswein, who wept as he and Benedict made their goodbyes to staff in the papal apartment on Feb. 28, has appeared visibly upset and withdrawn at times as he has been by Francis' side. The Vatican has said Francis' primary secretary will be Monsignor Alfred Xuereb, who had been the No. 2 secretary under Benedict.

Benedict's resignation — the emeritus Pope's personal choices about his future — have raised the question of how the Catholic Church will deal with the novel situation of having one reigning and one retired pope living side-by-side, each of them called "Pope," each of them wearing papal white and even sharing the same aide in Gaenswein.

After a few months in Castel Gandolfo, Benedict is to return to the Vatican to live in a converted monastery in the Vatican gardens, just a short walk from St. Peter's Basilica and the shrine devoted to the Madonna where Francis went to pray on one of his first walks as Pope.