Leave your thoughts on Foxe's Book of Martyrs here
Rome was a part of a larger system, the Beast of Babylon. This Beast has several heads, right? Because it is comprised of several kingdoms. The Church was not seated in Rome when John wrote his Revelation--he was talking about the powers that comprised the beast, not about the Catholic Church.
Albert Barnes is one of those guys that bends Revelation to mean what he wants it to mean--and since he's very anti-Catholic, he bends Revelation to mean that the Catholic Church is the enemy of God.
But that's not a safe conclusion to arrive at, if we want to remain true to the original symbolism of John, if we want to understand Revelation as the original audience would have understood it. Rome was part of Babylon, the "great city" that falls over and over again in Revelation as the Messiah appears. Jerusalem, too, is part of Babylon. Jerusalem is very deliberately the "whore" of Babylon, based on the previous imagery of the Old Testament.
Keep it in context, is all I'm stabbing at, here. Don't twist Revelation to be about what it was never intended to be about.
"Search the scriptures; for in them ye think ye have eternal life: and they are they which testify of me. And ye will not come to me, that ye might have life." John 5.39-40