[Web-masters note:]
"Middle English" not "Old English" is the term for what Geoffrey Chaucer (c. 1340-1400) wrote in.
Old English pre-dates the Norman invasion of England (1066), and is a Norse-looking Germanic language with no admixture of French.
Beowulf, for instance, was written in Old English.
Chaucer, author of the Canterbury Tales (also composed c. 1390) wrote in Middle English.