PERGAMOS 2:12,13 THRONE OF SATAN
“And to the angel of the church in Pergamos write, ‘These things said He who has the sharp sword with two edges: “I know your works, and where you dwell, even where Satan’s throne is” (Revelation 2:12,13). In the previous Smyrna period Satan invaded the place of worship (the “synagogue of Satan”) through legalism, and desire by the leadership for power and control. But in the Pergamos era Satan ascended the place of fellowship to the throne of rulership—“you dwell, where Satan’s throne is.”
A throne is a symbol of governing authority and is the source of the principles of government of the kingdom— “Righteousness and justice are the foundation of [God's] throne” (Psalm 97:2). “Satan’s throne,” on the other hand, is “the throne of iniquity, which devises evil by law” (Psalm 94:20). The devising of "evil by law" was a prime characteristic of the Pergamos era, as the emperor Constantine made Christianity the official religion of the Roman Empire in the early fourth century.
The persecutions of the Smyrna period had tended to strengthen rather than weaken the Church. Astute politician as he was, Constantine recognized that the persecution policy was a failure. While on the battlefield Constantine claimed to have had a vision in which he saw a cross with the inscription, “in this sign conquer.” Taking this to mean that he should embrace Christianity, he “baptized” his troops by marching them through the river, and had them write the Greek initials for Christ on their shields. He soon began to pass laws favoring Christianity over other religions, and by AD 321 heathen sacrifices had been outlawed, as well as work on Sunday. Gifts were made to the clergy, and great churches were erected in Rome, Jerusalem, and especially in Constantinople, the new capital of the empire.
Besides favoring the “true believers” with funds from the royal treasury, Constantine organized church councils to deal with heresy, took an active role in the decisions made, and banished and persecuted those who were declared “heretics.” Thus the union of church and state was established, which would be the model, both in the Byzantine Eastern Orthodox Church and in the western Roman Catholic Church until the Reformation over 1000 years later. “The imperial church came into existence, and a policy of imperial interference was fully developed. Departure from official orthodoxy had become a crime.”
For the “official” Church, it seemed like a dream come true. They were finally not only legal, but favored, so that they could get on with the mission Christ had given them to preach the Gospel in all the world. New “believers” were pouring into the Church, and the wealth and power of the Empire were at their disposal to create the kingdom of God on earth. They never dreamed of what a corrupting effect the union of church and state would have, or what kinds of heresies the half-converted pagans would bring with them into the Church.
 Wiliston Waker, The History of the Christian Church (New York, NY, C. Scribner, 1918) p. 128.