It would be outside our scope to enter into the details of the far-reaching consequences of this great event. For our present purpose it is sufficient to state that, with the empire in which it had been born and nurtured, the church was divided into two parts, which were thenceforth to develop independently, now in parallel, now in widely divergent lines. It will be convenient to regard the first chapter as dealing with the period between the institution of Christianity and the partition of the Roman Empire; and in the present chapter to discuss the interval between the latter event and the accession of Charles the Great. We thereby divide the history into two epochs of approximately four centuries each, with characteristics sufficiently well marked to distinguish one from the other. Following Marriott, we shall name the first the _primitive_, the second the _transitional_ period. We have seen that there is no evidence that vestments of any definite form were prescribed for use during the former epoch; we shall see in the present chapter how vestment-usage rapidly developed in the churches of the West till it culminated in the gorgeous enrichment of mediaeval times. Although the differences between the vestments of the Western and the Eastern churches consist largely in matters of detail, they are sufficiently conspicuous, and their histories are sufficiently divergent, to render their independent treatment advisable. We shall therefore postpone the discussion of the latter till we have investigated the evolution and subsequent elaboration of the former. The empire to which Honorius succeeded consisted of Italy, Spain, Gaul, and Britain. Although the evidence which is extant does not permit us to trace completely the history of vestments throughout this period, yet from scattered documents we are able to see that for the most part the development of ecclesiastical costume proceeded on the same lines throughout this vast area.