He could have chosen Paul. Or Clement. Or Pius. Or even Innocent — all earlier popes, all well-known quantities.

But when Cardinal Jorge Mario Bergoglio was elected pope on March 13, 2013, he picked a new name — “Francis.” It was a choice designed to send a clear message that he would be a new kind of pontiff with his own ideas for the world’s 1.2 billion Catholics.

“The choice of a name by a newly elected pope is an announcement of his agenda,” said Nancy Dallavalle, an associate professor of religious studies at Fairfield University. “In choosing Francis, Bergoglio sent a very direct message — change of course ahead.”

The choice was startling from the beginning. The College of Cardinals, the body that elects one of its own as pope, held five rounds of voting over two days. When it reached the required two-thirds majority, a cardinal appeared on the balcony above St. Peter’s Square and proclaimed, “Habemus Papam Franciscum.”

The throngs below cheered, but were confused. They clearly heard the Latin form of Francis, but which Francis? There had never been a Francis before. Was the new pontiff taking the name of St. Francis de Sales, the 16th-century bishop of Geneva known for his spiritual writings? Or was he honoring St. Francis Xavier, one of the first Jesuits, the order of priests to which Pope Francis belongs?

In fact, as the new pope revealed a few days later at a news conference with 5,000 journalists from around the world, he chose the name in honor of St. Francis of Assisi, a 13th-century Italian nobleman who shunned his family’s wealth and spent his life among the leprous and the poor, living even more simply than they did, in a rock hovel. He founded the Order of Friars Minor, also called the Franciscans.

Pope Francis said he was moved to take the name by his friend and fellow South American Cardinal Claudio Hummes. When it was clear Bergoglio won the more than 77 votes required for the papacy, Hummes hugged him, kissed him and said, “Do not forget the poor.”

“That word, the poor, lodged in me here,” Francis said, tapping his head. “It was then that I thought of St Francis. And then I thought of wars and about peace and that’s how the name came to me — a man of peace, a poor man.”

Other cardinals suggested different names, such as Adrian, after a great reforming pope, and Clement, a sort of stick-in-the-eye to Pope Clement XIV, the 18th-century pontiff who suppressed the Order of Jesuits to which Pope Francis belongs.

But St. Francis, who was known as “il poverello“ — the little poor man — resonated with him, Pope Francis said. “How I would like a church of the poor, for the poor.”

It is a name the pope has lived up to, in the eyes of many. He has upbraided bishops for their high-handedness, made financial reforms at the Vatican and has personally moved among the poor, even washing the feet of some Italian inmates during Lent.

And his landmark encyclical — the highest teaching of the church — calling on Christians to protect and honor the environment linked caring for the Earth to caring for the poor. He even named it in honor of St. Francis, giving it the title “Laudato Si’,” medieval Italian for “Praise Be” and a quotation from St. Francis’ most renowned prayer, “Canticle of Brother Sun.”

The Rev. Robert Wister, professor of church history at Seton Hall University, said Pope Francis has also lived up to St. Francis’ example in his personal lifestyle. He refused to move into the Apostolic Palace, the grand abode of his predecessors, choosing to remain instead in a Vatican guesthouse. Nor does he wear elaborate gold and gem-encrusted vestments or wear the famous — and expensive — handmade red-leather papal shoes.

“He is much more normal,” Wister said. “And I think it terrifies some of the high-living people in Rome. I think Francis is saying to all the bishops and priests, ‘Keep it simple.’ ”

(This story is part of a series on the papal visit produced in collaboration with USA Today.)