As you enter into the fourth century, it's persecuted by Diocletian. But then Constantine takes power, he's sympathetic to the Christians, he even convenes them in order to unify the Christians, to have a more unified sense of what it means to be Christian, in order to settle things like the Arian controversy, and he converts himself to Christianity. And as we exit the fourth century, you have Theodosius, who makes Christianity the official religion of the Roman Empire, and then begins to persecute other religions. Now what we're going to do in this video is continue the narrative, and in particular, we're going to see how there's an evolution between the church in the west and the church in the east. In previous videos, we already talk about how the Roman Empire itself is initially administered between west and east, and then that administration becomes more and more formal. Theodosius is the last emperor to truly rule both halves. They start getting ruled separately, and as you get into the latter half of the fifth century, the Western Empire itself falls to Germanic conquerors.