VATICAN CITY — On Sunday morning, Pope Francis descended to the grotto beneath St. Peter’s Basilica, where many past popes are buried, to pray at the tomb of Blessed Paul VI.

According to a Vatican communiqué, the Pope spent about half an hour in “recollection” and prayer before the tomb Aug. 6, the 39th anniversary of the late pope’s death.

Best known for Humanae Vitae (The Regulation of Birth) and his role in the Second Vatican Council, Paul VI was beatified by Pope Francis in 2014.

Not only has Francis acknowledged the important contribution of Blessed Paul VI to the universal Church, he has also followed closely in the late pontiff’s steps, particularly in his travels abroad, going to several of the places where his predecessor was the first pope to ever step foot.

This year also marks the 50th anniversary of Blessed Paul VI’s encyclicals Populorum Progressio (The Development of Peoples) and Sacerdotalis Caelibatus (The Celibacy of the Priest). Populorum Progressio was a key point of reference in Pope Francis’ establishment this year of the Dicastery for Promoting Integral Human Development.

Paul VI was born Giovanni Montini in 1897 in the town of Concesio in the Lombardy region of Italy. Ordained a priest in 1920 and consecrated as a bishop in 1954, he was appointed to the College of Cardinals in 1958.

At the age of 66 he was elected Bishop of Rome and chose the name Paul VI, in reference to the missionary spirit of St. Paul the Apostle.

He re-convoked the Second Vatican Council, which had automatically closed with the death of his predecessor, Pope St. John XXIII, and improved ecumenical relations with the Eastern Orthodox Churches.

In a historic move in December 1965, Blessed Paul VI and Ecumenical Patriarch Athenagoras I of Constantinople mutually lifted the excommunications that had been leveled against the leaders of both Churches in 1054.

Paul VI’s cause for canonization was opened in 1993. In December 2012, Benedict XVI recognized the heroic virtue of Paul VI, giving him the title of “Venerable.” In 2014, the Vatican approved a miracle attributed to his intercession, allowing for his beatification.

In his Oct. 19, 2014, homily for the beatification, Francis hailed Paul VI as “the great helmsman of the [Second Vatican] Council.”

He cited Blessed Paul VI’s words at the closing of Vatican II’s final session: “Perhaps the Lord has called me and preserved me for this service not because I am particularly fit for it, or so that I can govern and rescue the Church from her present difficulties, but so that I can suffer something for the Church, and in that way it will be clear that he, and no other, is her guide and Savior.”

“In this humility,” Pope Francis continued, “the grandeur of Blessed Paul VI shines forth: Before the advent of a secularized and hostile society, he could hold fast, with farsightedness and wisdom — and at times alone — to the helm of the Barque of Peter, while never losing his joy and his trust in the Lord.”