The Popes: 20 Important Popes from St. Peter to Leo XIV

For almost two thousand years, the Catholic Church has been led by a line of men stretching back to a Galilean fisherman. Some were martyrs. Some were scholars or reformers. A few were poor examples, and the Church has never hidden that. Together they tell an extraordinary story of God’s faithfulness to His Church.

What Is a Pope?

The word pope comes from a word meaning “father.” The pope is the Bishop of Rome and the successor of St. Peter. He is the visible source and foundation of the unity of the Church (CCC 882).

This office rests on the words of Jesus:

Thou art Peter; and upon this rock I will build my church, and the gates of hell shall not prevail against it. And I will give to thee the keys of the kingdom of heaven. (Matthew 16:18-19, Douay-Rheims)

Our Lord also prayed that Peter’s faith would not fail (Luke 22:32), and after the Resurrection told him three times to feed His sheep (John 21:15-17).

Peter went to Rome and died there as a martyr. The bishops of Rome who followed him inherited his responsibility, as the Catechism explains (CCC 880-882, 936-937).

How Is a Pope Chosen?

When a pope dies or resigns, the College of Cardinals gathers in Rome. Cardinals under the age of 80 enter a conclave in the Sistine Chapel, cut off from the outside world, and vote in secret. A two-thirds majority is required. Black smoke from the chapel chimney means no decision has been reached, and white smoke tells the world that there is a new pope.

20 Important Popes

Pope	Reign	Why he is remembered
St. Peter	d. about 64–67	Prince of the Apostles and the first pope, martyred in Rome
St. Fabian	236–250	A layman elected unexpectedly; martyred under the emperor Decius
St. Felix I	269–274	Led the Church during the persecutions of the third century
St. Marcellus I	308–309	Reorganized the Church in Rome after the persecution of Diocletian
St. Sylvester I	314–335	Pope during the reign of Constantine and the Council of Nicaea
St. Leo the Great	440–461	Defended the truth about Christ at Chalcedon and met Attila the Hun
St. Gregory the Great	590–604	Monk, teacher and Doctor of the Church; sent missionaries to England
St. Gregory VII	1073–1085	Reformer who defended the Church’s freedom from secular rulers
Innocent III	1198–1216	Called the Fourth Lateran Council and approved St. Francis’s way of life
St. Pius V	1566–1572	Carried out the reforms of Trent; published the Roman Missal of 1570
Bl. Pius IX	1846–1878	Defined the Immaculate Conception and convened the First Vatican Council
Leo XIII	1878–1903	Wrote Rerum Novarum on workers’ rights; promoted the Rosary
St. Pius X	1903–1914	Encouraged frequent Communion and Communion for young children
Pius XI	1922–1939	Established the feast of Christ the King; condemned Nazism in Mit brennender Sorge
Ven. Pius XII	1939–1958	Led the Church through World War II; defined the Assumption in 1950
St. John XXIII	1958–1963	Convened the Second Vatican Council
St. Paul VI	1963–1978	Brought the Council to completion; wrote Humanae Vitae
St. John Paul II	1978–2005	Traveled the world; promulgated the Catechism of the Catholic Church
Benedict XVI	2005–2013	Theologian and teacher; the first pope to resign in nearly 600 years
Francis	2013–2025	First pope from the Americas; proclaimed the Year of Mercy

Today the Church is led by Pope Leo XIV, born Robert Francis Prevost in Chicago and elected on May 8, 2025. According to the Holy See, he is the first pope from the United States and the first from the Order of St. Augustine. His order takes its rule from St. Augustine of Hippo.

What Infallibility Means, and Doesn’t Mean

Many people misunderstand this teaching. It does not say the pope is sinless, or that he is right about politics, science or anything else he happens to say.

The Catechism teaches that the pope is protected from error when, as supreme teacher of all the faithful, he definitively proclaims a doctrine of faith or morals (CCC 891). This has been done very rarely. The best-known examples are the definitions of the Immaculate Conception in 1854 and the Assumption in 1950.

Good Popes and Bad Popes

Honesty about the Church’s history includes admitting that some popes lived scandalous lives. This should not shake our faith. St. Peter denied Jesus three times, and Our Lord still entrusted the Church to him. The promise of Christ rests on His own faithfulness, not on the personal merits of those He calls.

Traditional Prayer for the Pope

Let us pray for our Pope, Leo. May the Lord preserve him, give him life, make him blessed upon the earth, and deliver him not to the will of his enemies. Amen.

A Prayer for the Church (Original Prayer)

Lord Jesus, You promised to be with Your Church always. Give our Holy Father wisdom, courage and good health. Bless our bishops and priests. Heal our divisions and make us one, as You and the Father are one. Amen.

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