Christianity was spread around the Roman Empire by the teachings of the apostles who travelled in the eastern part of the empire, North Africa and Rome to spread the gospels.
The work of Tertullian laid the foundations of Latin or Western Christianity from Carthage in Tunisia. It became the mainstream Christianity of the western part of the Roman Empire. Latin Christianity later came to be called Catholicism.
The foundation of Greek or Eastern Christianity were laid by the theologians of the Catechetical School of Alexandria in Egypt (which according to Jerome, who was a priest, theological and historian of Christianity, was founded by Mark the Apostle) and the School of Antioch in Syria. It became the mainstream Christianity of the eastern part of the Roman Empire. Later it came to be called Orthodox Christianity.
Arius, an ascetic Christian priest in Alexandria of Libyan origin, spread a dissident Christian doctrine which was popular around the empire. It was called Arian Christianity or Arianism and it was the main dissident Christian doctrine. It was suppressed from 380 on when the co-emperors Gratian and Theodosius I decreed that Latin and Greek Christianity were the sole legitimate religion of the Roman Empire in the Edict of Thessalonica of 380. Dissident Christian doctrines were branded as heretic and banned. The persecution of the Arian Christians begun soon after the issuing of this edict.
It was Charlemagne.
You see, HE NEVER DID Your welcome
Two conditions that helped the spread of the Gospel were (1) the excellent Roman roads, which facilitated travel, and (2) the Pax Romanum, or the Peace of Rome, which was the absence of wars enforced by the armed might of the Roman Empire.
No religion helped to save Roman culture. One religion spread through the Roman Empire in its later days and transformed Roman culture: Christianity.
Christianity did not easily spread through the Roman Empire. See the related question, "How did Christianity spread throughout the Roman Empire?"
Which teaching helped to spread Christianity in the Roman Empire? Slaves and the poor could hope for a better life after death. The Gospels written in Greek by his followers. Why did the Jews distrust King Herod?
Roman Empire
Charlemagne helped spread Christianity throughout the Frankish Empire and the lands he conquered. He spread Christianity through both peaceful conversion efforts and military conquests.
The apostles and Paul traveled throughout the region teaching others.
everything
The Romans spoke Latin. Latin spread through the empire because it was the language of the rulers. The spread of Latin was also helped by the establishment of colonies (settlements) of Romans and Latins around the empire.
Emperor Constantine I and his mother Helena.
It was Charlemagne.
Famine and disease spread throughout the empire
by avoiding ashoka's plans in 1100s
by avoiding ashoka's plans in 1100s
The Roman Empire was the geographical factor which first helped the spread of Christianity. It started in Judea, which was part of the Roman Empire. It was spread through this empire, especially its eastern part by Christian preachers. Originally the Christians were Jews who preached other Jews and followed Jewish law. Paul created a theology which opened Christianity to the gentiles (non-Jews) of the Roman Empire. He said that faith in Jesus and following his teaching was what was required for salvation. Therefore, you did not have to be a Jew or follow Jewish law to be a Christian. Christianity was endorsed by all but one of the emperors after Constantine the Great. This helped his spread. The co-emperors Gratian and Theodosius made mainstream Christianity (the Latin/Western Church and the Greek/eastern Church, which later came to be called Catholic and Orthodox respectively) the sole legitimate religion of the empire.