Christianity had remained, shaken but still strong, did much to keep up that continuity with the past upon which the life of the future depended. But beneath the general unity of its belief and its organisation, the Church was always in close touch with local life, and therefore had its local differences between place and place. It had still much to do in the more settled territories which were growing up into France, Germany and England. On the borders of the Empire it had further fresh ground to break and new races to mould. Even within the Empire it was before long to receive new invaders to educate and train: Normans and Danes were to bear witness, before our period ends, to the spirit and the strength in which it wrought. As is always the case when two powers are attempting the same task in different ways and by different means, there was inevitable rivalry and strife between Empire and Church as they grew together within one common society. But such generalisations give, after all, an imperfect picture. Beneath them the details of ecclesiastical life, in Papacy, diocese, parish and monastery, are also part of the common history, and have received the notice which they can therefore claim.
But if political history and ecclesiastical history present us with two centres of unity in a tangled field, thought, literature, and art were no less distinctly, though in other ways, guardians of unity and fosterers of future life. They too brought down from the past seeds for the new world to tend. So their story also, with its records of inheritance, plainer to read, especially in its Byzantine influences, than those of politics or ecclesiastical matters, is an essential part of our task. Politics, Religion, and Thought in all its many-sided fields, summed up for the future Western world all the remnants of the past which were most essential and fruitful for generations to come. They were the three great forces that made for unity and, with unity, for civilisation.
Taking all this for granted, then, we pass to the separate history of the individual countries just growing into states. For a time, they grow within the common mould of the Empire, and Carolingian traditions bind them to the past. Dimly to begin with, but with growing plainness, the realms of France, Germany, Italy, Lorraine, and Burgundy are seen taking their later territorial and constitutional shapes. England lay somewhat apart, insular, and therefore separated from the Empire, but by this very insularity everywhere exposed to Northmen and Danes. Here, too, as on the continent, statesman-like kings and far-sighted ecclesiastics worked together. The growth of territorial unity is easiest of all to trace, for it can be made plain in maps. But the growth of unity of thought and interests, of constitutions and social forms, is harder to see and to express;
