Were these parochial grammar schools to be found in England? The direct evidence is very slight. In a letter which Alcuin wrote to Offa, King of Mercia, about 792, he recommends to him a schoolmaster;[73] this schoolmaster, however, does not appear to possess a strong moral character, as Alcuin warns Offa not "to let him wander about with nothing to do nor to become a slave to drink, but to provide him with scholars and require him to teach these diligently." Then in another letter written by Alcuin and attributed to 797, the Bishop of Hexham is advised to pay attention to the education of boys and youths. It is stated in this letter that "it is a great work of charity to feed the poor with food for the body but a greater to fill the soul with spiritual learning." Apart from this evidence, there are a few references in Domesday Book which tend to support the idea of parochial schools and which we will subsequently consider. All that we can do here is to assume that, just as the Church in this country followed the general practice of the Church in the establishment of schools in connection with monasteries and cathedral churches, so she also followed the custom and precept of the Church in establishing schools in connection with the parish churches. CHAPTER III. THE EDUCATIONAL REVIVAL. The Danish invasions checked temporarily the remarkable educational progress this country was making. Beginning early in the ninth century, the era of Danish reconnoitring excursions closes with the year 855; the era of methodical plundering with the year 876. As a consequence of their various immigrations, the greater part of the English coasts were ruined and devastated. Towns and ecclesiastical buildings were plundered and burnt. "The Church with its civilising and cosmopolitan influences was for a time swept out of great districts which fell momentarily into heathen hands."[74] After a long and fierce struggle with the invaders, Alfred, the West Saxon king, held them in check, and compelled them to make peace with him. Subsequently, in the tenth century, through the successive efforts of Alfred's son, daughter, and grandson, the territory formerly yielded was regained.