The history of the Catholic Church begins with the teachings of Jesus Christ (c. 4 BC – c. AD 30), who lived in Galilee (later conquered by the Roman Empire). The Catholic Church teaches that it is the continuation of the early Christian community established by Jesus Christ, 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 who was appointed by Jesus in the New Testament as head of the church and ministered in Rome. By the end of the 2nd century, bishops began congregating in regional synods to resolve doctrinal and policy issues. By the 3rd century, the bishop of Rome began to act as a court of appeals for problems that other bishops could not resolve.
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, Christianity 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.