The universities of Oxford and Cambridge were
founded in 1167 and 1209 respectively, and
general literacy continued to increase over the
succeeding centuries, although books were still
copied by hand and therefore very expensive.
Over time, the commercial and political influence
of the East Midlands and London ensured that
these dialects prevailed (London had been the
largest city for some time, and became the
Norman capital at the beginning of the 12th
Century), and the other regional varieties came
to be stigmatized as lacking social prestige and
indicating a lack of education. The 14th Century
London dialect of Chaucer, although admittedly
difficult, is at least recognizable to us moderns
as a form of English, whereas text in the Kentish
dialect from the same period looks like a
completely foreign language.