Christianity emerged as a leading religion in the Imperial Roman age for a variety of factors. The teachings of Christ and Christian ideology including the concept of equality in the afterlife were obvious draws. However, people gravitated towards anything that would offer a new hope, especially as the stability of the late Empire continued to unravel. Some have suggested that the spread of Christianity had direct responsibility for the fall of the Empire, but it was more a symptom of the failings of Roman culture than the cause of the fall. Rome had suffered social disorder from its very foundations. Beginning with resistance to the Etruscan Kings, the political battles between Patricians and Plebes and continuing into the social wars fought by disenfranchised Italians seeking Roman citizenship; religious change was just another result of these various social occurences.
Early Christians, facing scorn at best and persecution at worst, depending on Emperor and the era, were forced to blend in with their Pagan counterparts. In order to celebrate the 'holidays' of their religion, the Christians used pre-existing holidays and festivals to blend in. Christmas, for example, was originally part of the great festival of the Winter Solstice, or the Saturnalia. By adopting this grand event as the celebration of Christ's birth, Christian revelry was allowed to take place, largely unnoticed.
By the fall of the western Empire (476 AD), Christianity was not only the official religion of the Roman world, but it had supreme authority in matters of morality and human behavior. Censorship played a large role as well. Historical documents of an incalculable number were destroyed or edited in order to prevent anti-Christian, or perceived anti-Christian thought. It is hard to imagine how much written history, and evidence of the ancient world, was lost forever due to this manipulation, but on the contrary, humanity must also recognize the great contribution of the Church to historical preservation.
It could be said that without the Roman Empire Christianity would not have spread so quickly, perhaps not spread at all! The Roman Empire became the Holy Roman Empire and continues in the form of Roman Catholic Church that has its heart in Rome’s Vatican City and a Holy Roman Emperor in the form of the Pope which comes from the Latin PAPA for Father. Catholic masses are still performed in Latin, the language of the Roman Empire. Some Roman buildings are still in use today as churches when most of the others have fallen into ruin.
Christianity spread like a wildfire after the downfall of Bar Kochba in about 135 CE. Almost one third of the Roman Empire became Christian in little more than 100 years.
That development evoked a great and bitter response from Rome, which saw it as a subversive religion that bred rebellion and diminished the power and stature of the Caesars. Therefore, the Romans persecuted the Christians without mercy, inventing all sorts of fiendish methods of public execution and torture in order to dissuade conversion to the new faith.
The historical phenomenon of Christianization, or Christianisation is the conversion of individuals to Christianity or the conversion of entire peoples at once. It also includes the practice of converting native pagan practices and culture, pagan religious imagery, pagan sites and the pagan calendar to Christian uses, due to the Christian efforts at proselytism (evangelism) based on the tradition of the "Great Commission".
The process of Christianization has at times been relatively peaceful and at times has been a very violent process, ranging from political conversions to adopt Christianity to military campaigns to force conversion onto native populaces often resulting in massacres and murder.
Various strategies and techniques employed in Christianization campaigns from Late Antiquity through the Middle Ages: Ancient holy sites were destroyed or converted to Christian churches, indigenous pagan gods were demonized, and traditional religious practices were condemned as witchcraft and even criminalized — sometimes upon penalty of death.
Islam
The term caliphate (from the Arabic خلافة or khilāfa) refers to the first system of government established in Islam, and represented the political unity of the Muslim Ummah (nation). In theory it is constitutional republic (see Constitution of Medina), meaning that the head of state (the Caliph) and other officials are representatives of the people who must govern according to Islamic law; which limits the government's power over citizens. It was initially led by Muhammad's disciples as a continuation of the political system the prophet established, known as the 'rashidun caliphates'. It represented the political unity, not the theological unity of Muslims as theology or mazhab was a personal matter. It was the world's first major welfare state. A "caliphate" is also a state which implements such a governmental system.
Sunni Islam dictates that the head of state, the caliph, should be selected by Shura - elected by Muslims or their representatives. Followers of Shia Islam believe the caliph should be an imam descended in a line from the Ahl al-Bayt. After the Rashidun period until 1924, caliphates, sometimes two at a single time, real and illusory, were ruled by dynasties. The first dynasty was the Umayyad. This was followed by the Abbasid, the Fatimid, and finally the Ottoman Dynasty.
The caliphate was "the core political concept of Sunni Islam, by the consensus of the Muslim majority in the early centuries."
The Spread of Islam started shortly after the death of the Islamic prophet Muhammad in 632. During his lifetime, the community of Muhammad, the ummah, was established in the Arabian Peninsula by means of conversion to Islam and conquering of territory. In the first centuries conversion to Islam followed the rapid growth of the Islamic world under the Rashidun and Umayyad Caliphs.
Muslim dynasties were soon established and subsequent empires such as those of the Abbasids, Almoravids, Seljuk Turks, Mughals in India and Safavids in Persia and Ottomans were among the largest and most powerful in the world. The Islamic world was composed of numerous sophisticated centers of culture and science with far-reaching mercantile networks, travelers, scientists, astronomers, mathematicians, doctors and philosophers, all of whom contributed to the Golden Age of Islam.
The activities of this quasi-political early ummah resulted in the spread of Islam as far from Mecca as China and Indonesia, the latter containing the world's largest Muslim population. As of October 2009, there were 1.571 billion Muslims, making Islam the second-largest religion in the world.
Increasing conversion to Islam paralleled the rapid military expansion of the Arab Empire in the first centuries after the Islamic prophet Muhammad's death. Muslim dynasties were soon established in North Africa, West Africa, throughout the Middle East and in Iran. It is generally agreed upon by historians that this took place through conversion of slaves and poor people, as well as waging wars on nearby tribes.
