According to Catholic teaching, the history of the Catholic Church begins with Jesus Christ and His teachings (c. 4 BC – c. AD 30), who lived in the Herodian Tetrarchy (later formed into the province of Judea by the Roman Empire). Jesus was born in Bethlehem, Judah, about 4 BC[citation needed]. His family fled to Egypt and subsequently returned to Nazareth, Galilee, approximately a year later. Galilee and the surrounding area were conquered by the Roman Empire in 6 CE, becoming part of the province of Judea. The Catholic Church is the continuation of the early Christian community established by Jesus Christ, as the Catholic Church teaches[1] that its bishops are the successors to Jesus's apostles, and the Bishop of Rome, also known as the Pope, is the sole successor to Saint Peter[2] who was appointed by Jesus in the New Testament as head of the church and ministered in Rome.[3][4] By the end of the 2nd century, bishops began congregating in regional synods to resolve doctrinal and policy issues.[5] By the 3rd century, the bishop of Rome began to act as a court of appeals for problems that other bishops could not resolve.[6]

Christianity spread throughout the early Roman Empire, despite persecutions due to conflicts with the pagan state religion. In 313, the struggles of the Early Church were lessened by the legalisation of Christianity by the Emperor Constantine I. In 380, under Emperor Theodosius I, Catholicism became the state religion of the Roman Empire by the decree of the Emperor, which would persist until the fall of the Western Empire, and later, with the Eastern Roman Empire, until the Fall of Constantinople. During this time, the period of the Seven Ecumenical Councils, there were considered five primary sees (jurisdictions within the Catholic Church) according to Eusebius: Rome, Constantinople, Antioch, Jerusalem and Alexandria, known as the Pentarchy.

The battles of Toulouse preserved the Catholic west, even though Rome itself was ravaged in 850, and Constantinople besieged. In the 11th century, already strained relations between the primarily Greek church in the East, and the Latin church in the West, developed into the East-West Schism, partially due to conflicts over Papal Authority. The fourth crusade, and the sacking of Constantinople by renegade crusaders proved the final breach. Prior to and during the 16th century, the Church engaged in a process of reform and renewal. Reform during the 16th century is known as the Counter-Reformation.[7] In subsequent centuries, Catholicism spread widely across the world despite experiencing a reduction in its hold on European populations due to the growth of Protestantism and also because of religious skepticism during and after the Enlightenment. The Second Vatican Council in the 1960s introduced the most significant changes to Catholic practices since the Council of Trent four centuries before.