Persecution of Christians in the Roman Empire in the context of "Roman imperial cult"

Constantine I (27 February 272 – 22 May 337), also known as Constantine the Great, or known mononymously as Constantine, was Roman emperor from AD 306 to 337 and the first Roman emperor to convert to Christianity. He played a pivotal role in elevating the status of Christianity in Rome, the Edict of Milan decriminalising Christian practice and ceasing Christian persecution. This was a turning point in the Christianisation of the Roman Empire. He founded the city of Constantinople (now Istanbul) and made it the capital of the Empire, which it remained for over a millennium.

Born in Naissus, a city located in the province of Moesia Superior (now Niš, Serbia), Constantine was the son of Flavius Constantius, a Roman army officer from Moesia Superior, who would become one of the four emperors of the Tetrarchy. His mother, Helena, was a woman of low birth, probably from Bithynia. Later canonised as a saint, she is credited for the conversion of her son in some traditions, though others believe that Constantine converted her. He served with distinction under emperors Diocletian and Galerius. He began his career by campaigning in the eastern provinces against the Persians, before being recalled to the west in AD 305 to fight with his father in the province of Britannia. After his father's death in 306, Constantine was proclaimed as augustus (emperor) by his army at Eboracum (York, England). He eventually emerged victorious in Civil wars of the Tetrarchy against the emperors Maxentius and Licinius to become the sole ruler of the Roman Empire by 324.

Paul, also named Saul of Tarsus, commonly known as Paul the Apostle or Saint Paul, was a Christian apostle (c. 5 – c. 64/65 AD) who spread the teachings of Jesus in the first-century AD. For his contributions towards the New Testament, he is generally regarded as one of the most important figures of the Apostolic Age, and he also founded several Christian communities in Asia Minor and Europe from the mid-40s to the mid-50s AD.

The main sources of information on Paul's life and works are Paul's letters and the Acts of the Apostles in the New Testament. Approximately half of its content documents his travels, preaching, and miracles. Paul was not one of the Twelve Apostles, and he did not know Jesus during his lifetime. Nonetheless, Paul was a contemporary of Jesus and personally knew eyewitnesses of Jesus such as his closest disciples (Peter and John) and brother James since the mid 30s AD, within a few years of the crucifixion (ca. 30–33 AD). He had knowledge of the life of Jesus and his teachings. According to the Acts, Paul lived as a Pharisee and participated in the persecution of early disciples of Jesus before his conversion. On his way to arrest Christians in Damascus, Paul saw a bright light, heard Christ speak, was blinded, and later healed by Ananias. After these events, Paul was baptized, beginning immediately to proclaim that Jesus of Nazareth was the Jewish messiah and the Son of God. He made three missionary journeys to spread the Christian message to non-Jewish communities.

John of Patmos (also called John the Revelator, John the Divine, John the Theologian; Ancient Greek: Ἰωάννης ὁ Θεολόγος, romanized: Iōannēs ho Theologos) is the name traditionally given to the author of the Book of Revelation. Revelation 1:9 states that John was on Patmos, an Aegean island off the coast of Roman Asia, where according to some biblical historians, he was exiled as a result of anti-Christian persecution under the Roman emperor Domitian.

Christian tradition has considered the Book of Revelation's writer to be the same person as John the Apostle, though some Christian scholars since medieval times have separated the disciple from the writer of Revelation. A minority of ancient clerics and scholars, such as Eusebius (d. 339/340), recognize at least one further John as a companion of Jesus, John the Presbyter.

Galerius Valerius Maximinus, born as Daza (Ancient Greek: Μαξιμίνος; 20 November c. 270 – c. July 313), was Roman emperor from 310 to 313. In 305 his uncle Galerius admitted him to the Tetrarchy with the rank of caesar, a controversial appointment which helped start the civil wars of the Tetrarchy in the following year. Maximinus Daza claimed the title of augustus in 310, sharing and often contesting power with Licinius. A committed pagan, he engaged in one of the last persecutions of Christians, and was the last person to hold the title of Pharaoh of Egypt. In 313 Maximinus Daza openly turned against Licinius and was routed at the Battle of Tzirallum. He died during the subsequent retreat, shortly after publishing an edict of tolerance restoring the Christians' freedoms.

The persecution of Christians can be traced from the first century of the Christian era to the present day. Christian missionaries and converts to Christianity have both been targeted for persecution, sometimes to the point of being martyred for their faith, ever since the emergence of Christianity.

Early Christians were persecuted at the hands of both Jews, from whose religion Christianity arose, and the Romans who controlled many of the early centers of Christianity in the Roman Empire. Since the emergence of Christian states in Late Antiquity, Christians have also been persecuted by other Christians due to differences in doctrine which have been declared heretical. Early in the fourth century, the empire's official persecutions were ended by the Edict of Serdica in 311 and the practice of Christianity legalized by the Edict of Milan in 312. By the year 380, Christians had begun to persecute each other. The schisms of late antiquity and the Middle Ages – including the Rome–Constantinople schisms and the many Christological controversies – together with the later Protestant Reformation provoked severe conflicts between Christian denominations. During these conflicts, members of the various denominations frequently persecuted each other and engaged in sectarian violence.

The 1st century was the century spanning AD 1 (represented by the Roman numeral I) through AD 100 (C) according to the Julian calendar. It is often written as the 1st century AD or 1st century CE to distinguish it from the 1st century BC (or BCE) which preceded it. The 1st century is considered part of the Classical era, epoch, or historical period. The Roman Empire, Han China and the Parthian Persia were the most powerful and hegemonic states.

During this century, the Roman Empire (ruled by the Julio-Claudian and Flavian dynasties) continued to be in a period of relative stability known as Pax Romana, withstanding a financial crisis in 33 and a civil war in 69. In Europe, Rome expanded into Britain and fought wars in Germania and Dacia. In Africa, Rome was challenged by Tacfarinas, who led his own Musulamii tribe and a loose and changing coalition of other Berber tribes before being defeated in 24. In West Asia, Rome defeated a Jewish rebellion (66–73) and fought a war with Parthia from 58–63, though the latter conflict was inconclusive. In East Asia, the Chinese Western Han dynasty was overthrown and replaced by the Xin dynasty in 9, which in turn faced its own rebel movements (namely the Red Eyebrows and Lulin), and was replaced by the Eastern Han dynasty in 25. The Eastern Han dynasty then faced and quelled a rebellion by the Trưng sisters (40–43). In 58, the Eastern Han dynasty entered a golden age with the Rule of Ming and Zhang, who were generally regarded as able administrators who cared about the common welfare of the people and who promoted officials with integrity. On its northern frontier, the Chinese dynasties waged intermittent war with the Xiongnu before emerging victorious in 91. The states of Funan and Xianbei were also established in this century.