The Cambridge History of English and American Literature in 18 Volumes (1907–21). Volume I. From the Beginnings to the Cycles of Romance. I. The Beginnings. § 4. National Strife. There came an end to all this when “the Danish terror” made a waste from the Humber to the Tyne. Northumbria had aided Rome and Charles the Great in the service of letters while the rest of Europe, save Ireland, had little to show, and now men were too busy fighting for home and freedom to think of letters. It was not until the days of Alfred that the tide began again to turn from continental to English shores, becoming a flood-tide when the second invasion of Northmen added a Norman strain to English blood.   14   The literature of the beginnings in England, therefore, appears to be the literature of its successive conquerors: English ousting Briton, Christian suppressing Pagan, Norman overruling English. For a time, the works of Englishmen have to be sought in Latin; for certain periods of civil struggle, of defeat, of serfdom, they cannot be found at all. But the literary spirit revives, having assimilated the foreign elements and conquered the conquerors. The “natural magic” of the Celtic mind, the Christian spirit which brought Greece and Rome in its train and “the matter of France” have all three become part of the Englishman’s intellectual heritage.   15