During the Anglo-Saxon period, English schools were among the finest in Europe. From English schools came the great masters whose writings instructed generations, centuries even, of Insular and continental students alike: one has only to think of the works of Aldhelm, Bede and Alcuin, which were copied and studied intensively up to the twelfth century and beyond. This achievement is all the more remarkable when one considers that the Anglo-Saxons were among the first peoples in Europe who were obliged to learn Latin as a foreign language if Christianity - a religion of the book par excellence - was to flourish. Throughout the Anglo-Saxon period, English schools benefited from the instruction of foreign masters domiciled there: the Roman monks who came with the Gregorian mission; Aidan and his fellow Irishmen who established a school at Lindisfarne in the mid-seventh century; Archbishop Theodore (d. 690) and Abbot Hadrian who taught at Canterbury in the late seventh century; John the Archchanter from St Peter's in Rome who taught at Wearmouth-Jarrow at roughly the same time; Grimbald of Saint-Bertin, John the Old Saxon and Asser of St David's in Wales, all of whom were invited by King Alfred in the late ninth century to assist him in the establishment of English schools; then men such as Lantfred and Abbo, both from Fleury, who in the later tenth century spent brief periods at the schools of Winchester and Ramsey respectively; and finally scholars such as Goscelin and Folcard, both from Saint-Bertin, who resided in England in the later eleventh century.