At the beginning of this epoch classical genius was already extinct, and the purity of the classical tongues was yielding rapidly to the corruptions of the provinces and of the new dialects. Many other causes conspired to work great changes in the fabric of society, and in the manifestations of human intellect. Throughout this period the treasures of Greek and Latin literature, exposed to the danger of perishing and impaired by much actual loss, exerted no influence on the minds of those who still used the tongues to which they belong. Greek letters, as we have seen, decayed with the Byzantine power, and the vital principle in both became extinct long before the sword of the Turkish conqueror inflicted the final blow. The fate of Latin literature was not less deplorable. When province after province of the Roman dominions was overrun by the northern hordes, when the imperial schools were suppressed and the monuments of ancient genius destroyed, an enfeebled people and a debased language could not withstand such adverse circumstances. During the seventh and eighth centuries Latin composition degenerated into the rudeness of the monkish style. The care bestowed by Charlemagne upon education in the ninth century produced some purifying effect upon the writings of the cloister; the tenth was distinguished by an increased zeal in the task of transcribing the classical authors, and in the eleventh the Latin works of the Normans display some masculine force and freedom. Latin was the repository of such knowledge as the times could boast; it was used in the service of the church, and in the chronicles that supplied the place of history, but it was not the vehicle of any great production stamped with true genius and impressing the minds of posterity. Still, genius was not altogether extinguished in every part of Europe. The north, which sent out its daring tribes to change the aspect of civil life, furnished a fresh source of mental inspiration, which was destined, with the recovered influence of the classic spirit and other prolific causes, to give birth to some of the best portions of modern literature.