As time goes on, after the tenth century, it is noticeable that the more beautiful a manuscript becomes in its writing the less accurate becomes its Latinity. And so the monks who once were noted for learning, gradually lose their grip on Latin. The manuscripts executed in Benedictine abbeys became inaccurate--almost illiterate. Faults of ignorance of words; misrendering of proper names; blundering in the inept introduction of marginal notes and confounding such notes with the text, showing that the heart of the copyist was not in his work nor his head capable of performing it. His hand is simply a machine, which when it goes wrong does so without remorse and without shame. So in the greater houses, men were appointed whose sole business was to supervise the copyists--in fact, to supply the brains, while the scribe furnished the manipulation of the pen. Even they, however, did not always succeed to perfection, as very few of them were too well furnished with scholarship. There were not many Alcuins or Theodulfs in the twelfth century. What they did usually keep free from serious error were the books used in their own services. It was the aim, particularly among the Cistercian houses, to have their liturgical texts absolutely without fault. In respect of illumination, there was a great quarrel between the Abbey of Citeaux and that of Cluny. The great Abbey of Clugny (or Cluny) in ancient Burgundy was founded in 910, and in the course of a century or obtained a degree of splendour, influence, and prosperity unrivalled by any other mediæval foundation. It possessed enormous wealth and covered Western Europe with its affiliated settlements. Under Peter the Venerable, when the controversy began, it was the chief monastic centre of the Christian world. The words of Pope Urban II., when addressing the community, were: "Ye are the light of the world."