Centuries before their continental neighbours, for whom Latin long remained the major language of writing, the Anglo-Saxons had an extensive literature in their own vernacular – Old English. The opportunity for widespread literacy had come to them with their conversion to Christianity, which began with St Augustine's mission to Canterbury in 597.Within only a few years, the lawcode of the kingdom of Kent had been put into English, the first vernacular document that we know of (see Section II), and by the time of the Norman Conquest in 1066 there was no area of written discourse not represented by works in OE, whether as translations or original compositions. Nevertheless, it was Latin which remained the official language of the church throughout the Anglo-Saxon period, and far beyond it. Key theological texts and the Bible were all in Latin, and so were divine services, and therefore would-be monks and priests among the native population (whose mother tongue was OE in its various dialectal varieties) had to learn it. A priority for the missionaries at Canterbury, and their successors throughout the group of Anglo-Saxon kingdoms which would eventually become England, was thus the setting up of schools. All monasteries and cathedrals of any size needed one, and naturally the medium of instruction, to begin with at least, would have to be the vernacular.