"In response to the appeal of Emperor Alexis I, Pope Urban II made his speech at the Council of Clermont urging every social class to embark on a righteous to rescue the Holy Land from the hands of the "infediles.""
"The main dialect regions during this time are usually referred to as Northern, Midlands, Southern and Kentish, although they were really just natural developments from the Northumbrian, Mercian, West Saxon and Kentish dialects of Old English. Within these, though, a myriad distinct regional usages and dialects grew up, and indeed the proliferation of regional dialects during this time was so extreme that people in one part of England could not even understand people from another part just 50 miles away."
"The Norman dynasty established by William the Conqueror ruled England for over half a century before the period of succession crisis known as the Anarchy (1135–1154). Following the Anarchy, England came under the rule of the House of Plantagenet, a dynasty which later inherited claims to the Kingdom of France."
So the Normans were still in England. After the Normans left things got better, in terms of understanding one another.