William the Conqueror, the Duke of Normandy, invaded and conquered England and the Anglo-Saxons in 1066 AD. The new overlords spoke a dialect of Old French known as Anglo-Norman. The Normans were also from Germany and Anglo-Norman was a French dialect that had considerable Germanic influences in addition to the basic Latin roots.
The next wave of innovation in English came with the Renaissance. The revival of classical scholarship brought many classical Latin and Greek words into the language. Many people having difficulty understanding Shakespeare would be surprised to learn that he wrote in modern English. Many familiar words and phrases were coined or first recorded by Shakespeare, some 2,000 words and many catch-phrases are his. "One fell swoop," "vanish into thin air," and "flesh and blood" are all Shakespeare's. Words he bequeathed to the language include "critical," "leapfrog," "majestic," "dwindle," and "pedant."
Two other major factors influenced the language and served to separate Middle and Modern English.
The first was the Great Vowel Shift. This was a change in pronunciation that began around 1400. While modern English speakers can read Chaucer with some difficulty, Chaucer's pronunciation would have been completely unintelligible to the modern ear. Shakespeare, on the other hand, would be accented, but understandable. Vowel sounds began to be made further to the front of the mouth and the letter "e" at the end of words became silent. The shift is still not over, however, vowel sounds are still shortening although the change has become considerably more gradual.
The last major factor in the development of Modern English was the advent of the printing press. William Caxton brought the printing press to England in 1476. Books became cheaper and as a result, literacy became more common. Publishing for the masses became a profitable enterprise, and works in English,