The topic of this chapter returns to a theme discussed in Chapter 7 concerning the plural nature of Europe and offers an interlude before a more detailed survey of the twentieth century, which follows in the next chapters. The emphasis so far has been on identifying underlying processes of unity and departures from broadly common civilizational structures. The civilizational background has itself been diverse with routes within it that were shaped by the western and eastern currents of Roman civilization, the Russian offshoots of the Byzantine tradition that developed in the east, and the multifarious impact of Islam on the Iberian and the south eastern regions. Four inter-linked civilizational currents formed, what was termed, the European inter-civilizational constellation: the Greco-Roman, western Christianity, the Byzantine-Russian and Ottoman-Islamic traditions. The unity and diversity of Europe derives from its civilizational diversity, which as we have seen also established the basis of different traditions of empire.