In Revelations 2:13, the Messiah says that "Satan's throne" is in Pergamum, a city in western Anatolia (today called Asia Minor or Turkey). According to Strong's Concordance, the Greek word Thronos ("throne", or "seat" in KJV) indicates a seat of power, authority and government. Therefore, I believe that the simplest explanation for why the Messiah said "Satan's throne" is in Pergamum is because Pergamum was the Roman Capital -- to wit, the "seat of Roman Government" -- of Asia. Now, here is a map of the Roman province of Asia: http://www.unrv.com/images/provinces/asiaminor.jpg As you can see, the Roman province of Asia encompasses all "seven churches which are in Asia" (Rev 1:4). In fact, the Messiah seems to be using the Roman name of the region, "Asia". Thus, I propose that the reason why "Satan's throne" is in Pergamamum is because Pergamum was the Roman provincial capital -- the "seat of Rome's government" of the area. After all, Revelations refers to Rome as "the great whore that sitteth upon many waters(17:1)" and as "BABYLON THE GREAT, THE MOTHER OF HARLOTS AND ABOMINATIONS OF THE EARTH (17:5)". Rome is clearly painted as the arch-enemy of God's designs, and that is satan. Therefore, Pergamum is called "Satan's throne" (Rev 2:13) simply because Pergamum was the provincial capital of Rome, the "great satan" of the first century CE.