The Roman Autocracy (284 C.E. to 395 C.E.) was developed by the Emperors Diocletian (284 - 305) and Constantine (306 - 337).  Diocletian reorganized the Roman Empire and concentrated his own rule on the Eastern half.  Constantine established Constantinople at the location of the old Greek city named Byzantium.  

Emperors of the Autocracy
    Diocletian 284 - 305        
    Constantine 306 - 337
    Julian 360 - 363
    Valens 364 - 378
     Theodosius "The Great" 378 - 395  

These administrative shifts to the East marked the eventual break-up of the Roman Empire, after 395 C.E., into a Western Roman Empire and an Eastern Roman Empire.  This Eastern Roman Empire came to be called the Byzantine Empire especially after rule of Justinian when the Latin ceased to be the official language of the Emperors.

This Eastern Roman (Byzantine) Empire was a Christian state that retained a good deal of the Classical Greco-Roman culture.  Here again, the pattern was set by Constantine during the days of the Autocracy.  Constantine legalized Christianity in 313 with the Edict of Milan and favored Christianity with gifts.  By the end of the Autocracy, the Emperor Theodosius (378 - 395) made Christianity into the official religion of the Roman Empire.

Constantine also established a tradition of caesaropapism, where Church and State are intimately connected.  The Emperor Constantine presided over the Council of Nicaea in 325 that condemned Arianism as a heresy and established the Nicaean Creed of the Trinity, which is still used as the basic definition of what it means to be a Christian. Constantine was not even a Christian at the time of this first oecumenical Church Council.  He may have become a Christian only on his deathbed.

Caesarepapism remained an important feature of the Byzantine Empire and of the Greek Orthodox Church tradition.

With many ups and downs, this Byzantine Empire lasted until 1453 C.E. when it was finally conquered by the Ottoman Turks using cannons to smash through the thick fortifications of Constantinople. 

In 378 C.E. at the Battle of Adrianople the Visigoths defeated the Romans and the Emperor Valens was killed.  The government in Constantinople deliberately persuaded the Visigoths to move on toward the West.  The Roman Imperial Government centered on the East was willing to surrender the West to the Germanic barbarians.  In 410 C.E., the Visigoths took Rome.

Theodosius was the last Roman Emperor who ruled both the East and the West.  With his death, his two sons each inherited half the Empire.  From 395 to 476 C.E., Western Roman Emperors tried ineffectively to establish their authority over the invading Germanic tribes.  In 476 C.E., Odoacer ousted the last Roman Emperor of the West named Romulus Augustulus.  Impressive names for a weak ruler.  In the West, the Bishops of Rome were left to deal with the Germanic settlers.

Muslim Empire

Brief Biography of Muhammad  

Muhammad was born about 570 C.E. in Mecca and died 632.
    His father died before he was born.
    His mother died when he was six.
    He married a wealthy widow, Khadijah, when he was 25 and she was 40.  Khadija died in 619.

He later married three more times.

            Aisha, the daughter of Abu Bakr, 
            Hafsah, the daughter of Umar, and
            Habiba, the daughter of Abu Sufyan (Muhammad's former enemy).

According to Islamic tradition, Khadijah, bore Muhammad six children, one of whom was his favorite.

In 610 C.E., Muhammad received a revelation from the Angel Gabriel that Muhammad was the Messenger of God.  He received a number of recitations, which were collected into the holy book of Islam, the Koran or Qur'an.

Allah is the Arabic word for God.  All three monotheistic religions--Judaism, Christianity, and Islam--believe in the one God.

In 619, his uncle Abu Talib, who was the head of the Hashim clan of the dominant Quraysh tribe, and Muhammad's wife Khadijah died.  The new clan leader refused to give Muhammad protection.

In 622, Muhammad and 70 of his followers fled from Mecca to Yathreb, later called Medina (City of the Prophet).  This flight is called the Hegira and is commemorated during the Moslem month of Ramadan.  During Ramadan, Muslims may not eat from sunrise through sunset.

"Muhammad had been invited to Medina to act as a peace arbitrator among the feuding tribes.  Medina was a city with three Jewish clans as well as a large Arab population.  Muhammad made himself the leader of the Arabs of the city and eventually eliminated the Jews (some by execution) who resisted his efforts at conversion. 

“He began attacks on the caravans of Mecca, and this led to a large-scale war.  In 627, he successfully resisted a siege of Medina by a force of ten thousand Meccans. 

“In 629, he reached a truce with the Meccan leaders and, in 630, he marched into Mecca with little bloodshed.  He granted a general amnesty  and made Mecca the center of worship of his new religion. 

“When Muhammad died in 632, Islam was the religion of the greater part of the Arabian peninsula." 

 (Thomas J. Kehoe, Harold E. Damerow, and Jose Marie Duvall, Exploring Western Civilization to 1648:  A Worktext for the Active Student (Dubuque, Iowa:  Kendall/Hunt Publishing Company, 1997), p. 276).

The following link gives a brief biography of Muhammad

Islamic Religion

1 A.H. = 622 C.E.

Development of Islamic Power

Monasticism has its roots in the eastern half of the Roman Empire.  It began when hermits withdrew from the world.  The Greek word for hermit is eremos.  Hermits who lived alone in an ascetic way of life established what came to be called eremitical monasticism.
        St. Anthony (~250 - 355) is considered to be the first eremitical monk.  He lived in the Egyptian desert after having given up all his worldly possessions.  He made the transition from hermit to monk.  His saintliness attracted others who formed a cluster of hermits.
        When groups of devout people form a community under a communal rule, then we have moved from eremitical (hermit) monasticism to cenobitic (communal) monasticism.  Pachomius (~290 - 346) is considered to be the first to have written a rule for communal living based on chastity, poverty, physical labor, and obedience to the abbot.  Basil (329 - 379) and John Cassian (360 - 435) and Cassiodorus (~485 - ~585) were early founders of monasteries. 
        St. Benedict of Nursia, 480 to 543 C.E., is considered to be the founder of Western Monasticism.  The Benedictine Rule for living communally became the standard rule for monasteries and nunneries in the West.  He founded Monte Cassino as a  Benedictine monastery.  Many such monasteries followed based on the Benedictine Rule.

   My WEB page on Christianity contains additional information on the Germanic Invasions, the fall of the Western Roman Empire, and the development of Western, Catholic, Christianity.