The history of English is conventionally, if perhaps too neatly, divided into three periods usually called Old English (or Anglo-Saxon), Middle English, and Modern English. The earliest period begins with the migration of certain Germanic tribes from the continent to Britain in the fifth century A.D., though no records of their language survive from before the seventh century, and it continues until the end of the eleventh century or a bit later. By that time Latin, Old Norse (the language of the Viking invaders), and especially the Anglo-Norman French of the dominant class after the Norman Conquest in 1066 had begun to have a substantial impact on the lexicon, and the well-developed inflectional system that typifies the grammar of Old English had begun to break down. The following brief sample of Old English prose illustrates several of the significant ways in which change has so transformed English that we must look carefully to find points of resemblance between the language of the tenth century and our own. It is taken from Aelfric's "Homily on St. Gregory the Great" and concerns the famous story of how that pope came to send missionaries to convert the Anglo-Saxons to Christianity after seeing Anglo-Saxon boys for sale as slaves in Rome:
