Many sacred beliefs of our Catholic faith can be traced to the 21 ecumenical councils held since the fourth century.

The 381 Council of Constantinople solidified Trinitarian doctrine, affirmed the Holy Spirit’s divinity, and reshaped the Nicene Creed, marking a turning point in early Christian theology.

This year, the universal Church celebrates the 1,700th anniversary of the Council of Nicaea, the first ecumenical council ...

Istanbul marked the 1,700th anniversary of the First Council of Nicaea, the groundbreaking gathering convened in 325 by ...

A quiet yet symbolically significant gathering took place on May 17 at the Coptic Orthodox Patriarchate in Cairo.

But the new pope, in 2025, has done something more than mark an anniversary. By choosing the name “Leo” and explicitly ...

At the Council of Chalcedon in 451, Leo's teachings triumphed, establishing the belief in Christ's dual nature—both human and divine—still held by the Church today. Leo II (Pope from 682-683 ...

Pope Leo I tangled with Attila the Hun and won. Pope Leo III crowned Charlemagne as the first Holy Roman Emperor. This is the ...

The Pope’s baptismal name was revealed after ... Additionally, he taught and led the Council of Chalcedon to affirm that Jesus was one fully divine and one fully human nature and that he was ...

Indeed, the first Pope Leo — known as Leo the Great — served 440-461. He is best known as the pope who persuaded Attila the Hun to turn back from the invasion of Italy. His thinking was also central ...

Pope Leo XIV, formerly Bob from Chicago ... was his contribution to the Council of Chalcedon (451), an ecumenical council of enormous importance in the history of the church that clarified ...

At the 451 Council of Chalcedon, the fourth ecumenical council ... In a letter to Archbishop Flavian of Constantinople, the pope explained that Christ has a divine and a human nature which exist ...