Christendom historically refers to the Christian states, Christian empires, Christian-majority countries and the countries in which Christianity dominates, prevails, or that it is culturally or historically intertwined with.
Constantine I, also known as Constantine the Great, was Roman emperor from AD 306 to 337. He was the first emperor to convert to Christianity. Born in Naissus, Dacia Mediterranea, he was the son of Flavius Constantius, a Roman army officer of Illyrian origin who had been one of the four rulers of the Tetrarchy. His mother, Helena, was a Greek woman of low birth and a Christian. Later canonized as a saint, she is traditionally attributed with the conversion of her son. Constantine served with distinction under the Roman emperors Diocletian and Galerius. He began his career by campaigning in the eastern provinces before being recalled in the west to fight alongside his father in the province of Britannia. After his father's death in 306, Constantine was acclaimed as imperator by his army at Eboracum. He eventually emerged victorious in the civil wars against emperors Maxentius and Licinius to become the sole ruler of the Roman Empire by 324.
The history of Christianity concerns the Christian religion, Christian countries, and the Christians with their various denominations, from the 1st century to the present. Christianity originated with the ministry of Jesus, a Jewish teacher and healer who proclaimed the imminent Kingdom of God and was crucified c. AD 30–33 in Jerusalem in the Roman province of Judea. His followers believe that, according to the Gospels, he was the Son of God and that he died for the forgiveness of sins and was raised from the dead and exalted by God, and will return soon at the inception of God's kingdom.
Mithraism, also known as the Mithraic mysteries or the Cult of Mithras, was a Roman mystery religion centered on the god Mithras. Although inspired by Iranian worship of the Zoroastrian divinity (yazata) Mithra, the Roman Mithras is linked to a new and distinctive imagery, with the level of continuity between Persian and Greco-Roman practice debated. The mysteries were popular among the Imperial Roman army from about the 1st to the 4th century CE.
The Edict of Milan was the February 313 AD agreement to treat Christians benevolently within the Roman Empire. Western Roman Emperor Constantine I and Emperor Licinius, who controlled the Balkans, met in Mediolanum and, among other things, agreed to change policies towards Christians following the edict of toleration issued by Emperor Galerius two years earlier in Serdica. The Edict of Milan gave Christianity legal status and a reprieve from persecution but did not make it the state church of the Roman Empire. That occurred in AD 380 with the Edict of Thessalonica.
Christianization or Christianisation is to make Christian; to imbue with Christian principles; to become Christian. It can apply to the conversion of an individual, a practice, a place or a whole society. It began in the Roman Empire, continued through the Middle Ages in Europe, and in the twenty-first century has spread around the globe.
Late antiquity is the time of transition from classical antiquity to the Middle Ages, generally spanning the 3rd–7th century in Europe and adjacent areas bordering the Mediterranean Basin. The popularization of this periodization in English has generally been credited to historian Peter Brown, after the publication of his seminal work The World of Late Antiquity (1971). Precise boundaries for the period are a continuing matter of debate, but Brown proposes a period between the 3rd and 8th centuries AD. Generally, it can be thought of as from the end of the Roman Empire's Crisis of the Third Century (235–284) to the early Muslim conquests (622–750), or as roughly contemporary with the Sasanian Empire (224–651). In the West, its end was earlier, with the start of the Early Middle Ages typically placed in the 6th century, or earlier on the edges of the Western Roman Empire.
During the reign of the Roman Emperor Constantine the Great, Christianity began to transition to the dominant religion of the Roman Empire. Historians remain uncertain about Constantine's reasons for favoring Christianity, and theologians and historians have often argued about which form of early Christianity he subscribed to. There is no consensus among scholars as to whether he adopted his mother Helena's Christianity in his youth, or, as claimed by Eusebius of Caesarea, encouraged her to convert to the faith he had adopted.
Christian apologetics is a branch of Christian theology that defends Christianity.
The growth of Christianity from its obscure origin c. 40 AD, with fewer than 1,000 followers, to being the majority religion of the entire Roman Empire by AD 350, has been examined through a wide variety of historiographical approaches.
Christianity is the largest religion in Europe. Christianity has been practiced in Europe since the first century, and a number of the Pauline Epistles were addressed to Christians living in Greece, as well as other parts of the Roman Empire.
Paganism is commonly used to refer to various religions that existed during Antiquity and the Middle Ages, such as the Greco-Roman religions of the Roman Empire, including the Roman imperial cult, the various mystery religions, religions such as Neoplatonism and Gnosticism, and more localized ethnic religions practiced both inside and outside the empire. During the Middle Ages, the term was also adapted to refer to religions practiced outside the former Roman Empire, such as Germanic paganism, Egyptian paganism and Baltic paganism.
Christians were persecuted, sporadically and usually locally, throughout the Roman Empire, beginning in the 1st century AD and ending in the 4th century. Originally a polytheistic empire in the traditions of Roman paganism and the Hellenistic religion, as Christianity spread through the empire, it came into ideological conflict with the imperial cult of ancient Rome. Pagan practices such as making sacrifices to the deified emperors or other gods were abhorrent to Christians as their beliefs prohibited idolatry. The state and other members of civic society punished Christians for treason, various rumored crimes, illegal assembly, and for introducing an alien cult that led to Roman apostasy. The first, localized Neronian persecution occurred under Emperor Nero in Rome. A more general persecution occurred during the reign of Marcus Aurelius. After a lull, persecution resumed under Emperors Decius and Trebonianus Gallus. The Decian persecution was particularly extensive. The persecution of Emperor Valerian ceased with his notable capture by the Sasanian Empire's Shapur I at the Battle of Edessa during the Roman–Persian Wars. His successor, Gallienus, halted the persecutions.
Christianity in Asia has its roots in the very inception of Christianity, which originated from the life and teachings of Jesus in 1st-century Roman Judea. Christianity then spread through the missionary work of his apostles, first in the Levant and taking roots in the major cities such as Jerusalem and Antioch. According to tradition, further eastward expansion occurred via the preaching of Thomas the Apostle, who established Christianity in the Parthian Empire (Iran) and India. The very First Ecumenical Council was held in the city of Nicaea in Asia Minor (325). The first nations to adopt Christianity as a state religion were Armenia in 301 and Georgia in 327. By the 4th century, Christianity became the dominant religion in all Asian provinces of the Eastern Roman Empire.
Christianity began as a Second Temple Judaic sect in the 1st century in the Roman province of Judea, from where it spread throughout and beyond the Roman Empire.
Christianity in the 4th century was dominated in its early stage by Constantine the Great and the First Council of Nicaea of 325, which was the beginning of the period of the First seven Ecumenical Councils (325–787), and in its late stage by the Edict of Thessalonica of 380, which made Nicene Christianity the state church of the Roman Empire.
Early Christianity, or Palaeochristianity, describes the historical era of the Christian religion up to the First Council of Nicaea in 325. Christianity spread from the Levant, across the Roman Empire, and beyond. Originally, this progression was closely connected to already established Jewish centers in the Holy Land and the Jewish diaspora. The first followers of Christianity were Jews who had converted to the faith, i.e. Jewish Christians. Early Christianity contains the Apostolic age and is followed by, and substantially overlaps with, the Patristic era.
Christianity in late antiquity traces Christianity during the Christian Roman Empire — the period from the rise of Christianity under Emperor Constantine, until the fall of the Western Roman Empire. The end-date of this period varies because the transition to the sub-Roman period occurred gradually and at different times in different areas. One may generally date late ancient Christianity as lasting to the late 6th century and the re-conquests under Justinian of the Byzantine Empire, though a more traditional end-date is 476, the year in which Odoacer deposed Romulus Augustus, traditionally considered the last western emperor.
Christianity became the official religion of the Roman Empire when Emperor Theodosius I issued the Edict of Thessalonica in 380, which recognized the catholic orthodoxy of Nicene Christians in the Great Church as the Roman Empire's state religion. Most historians refer to the Nicene church associated with emperors in a variety of ways: as the catholic church, the orthodox church, the imperial church, the imperial Roman church, or the Byzantine church, although some of those terms are also used for wider communions extending outside the Roman Empire. The Eastern Orthodox Church, Oriental Orthodoxy, and the Catholic Church all claim to stand in continuity from the Nicene church to which Theodosius granted recognition.
Persecution of pagans in the late Roman Empire began during the reign of Constantine the Great in the military colony of Aelia Capitolina (Jerusalem), when he destroyed a pagan temple for the purpose of constructing a Christian church. Rome had periodically confiscated church properties, and Constantine was vigorous in reclaiming them whenever these issues were brought to his attention. Christian historians alleged that Hadrian had constructed a temple to Aphrodite on the site of the crucifixion of Jesus on Golgotha hill in order to suppress Christian veneration there. Constantine used that to justify the temple's destruction, saying he was simply reclaiming the property. Using the vocabulary of reclamation, Constantine acquired several more sites of Christian significance in the Holy Land.
