Alcuin was a pupil at York cathedral school, and became headmaster of the school in 778. During his time as headmaster at York Alcuin built up a fine library and made the school one of the most important centres of learning in Europe. He wrote a long poem describing the men associated with York's history before he left for the continent. In 781 he accepted an invitation of Charlemagne to go to Aachen to a meeting of the leading scholars of the age. He became head of Charlemagne's Palace School at Aachen and there he developed the Carolingian minuscule, a clear script which has become the basis of the way the letters of the present Roman alphabet are written. Before leaving Aachen, Alcuin was responsible for the most precious of Carolingian codices, now called the Golden Gospels. These were a series of illuminated masterpieces written largely in gold, often on purple coloured vellum. In 796 Alcuin became abbot of the Abbey of St Martin at Tours, where he had his monks continue to work with the Carolingian minuscule script. Alcuin wrote elementary texts on arithmetic, geometry and astronomy at a time when there was just beginning a renaissance in learning in Europe, a renaissance mainly led by Alcuin himself. His lesson books were written in a question - and - answer format. However his work in this area, unlike the inspired calligraphy he developed, shows little originality.