EMPEROR CONSTANTINE
Constantine was Emperor of the Roman Empire between 306 AD - 337 AD (31 years), and sole ruler of the Roman Empire from 324 AD until his death in 337 AD (13 years).
In his reign between 306 AD and 324 AD he shared the Emperors throne with 3 other Emperors at the same time. The Roman Empire had become so large and so diverse that it was difficult to manage, so it was divided into 4 parts, each with an Emperor. Constantine didn't like sharing the throne so Civil War between the Emperors broke out. After Constantine eliminated the other three he became the sole Emperor in 324 AD. He also murdered his wife and his eldest son in order to shore-up his power and eliminate any opposition.
The Roman Empire had already been in decline for 150 years before Constantine. Constantine, as sole Emperor realized he needed a "Social Glue" to help hold the Empire together. Like most all Empires throughout history one of the best social glues used to control the citizens was/is Religion... but the Empire was so vast, and it held so many different people with different Religious Views, how could that be achieved?
After Jesus, his Apostles and Disciples went everywhere to preach the teachings of Jesus: France, England, Spain, Italy, Africa, Middle East, Russia, and many other places. Up to this time the followers of Jesus (lets call them Christians) had been persecuted and outlawed by the Roman Government. Constantine realized that the teachings of Jesus and these Christians were everywhere in the Empire, so he decided to make Christianity Legal and use it as a Social Glue that would help hold the Empire together... but how could he create such a powerful and influential organization? Good question.
So Emperor Constantine looked East, to the Empire next door - the Persian Empire which had been around for a thousand years and had a central, official State Controlled Religion... Zoroastrianism.
NOTE: To learn how Constantine achieved his church development read the next Writing titled, Structural Dogma (click here)