A. The English language began somewhere around 500 A.D. when Germanic tribes, the Angles and the Saxons, began to invade what is now called England (originally Angleland). As the English speaking people had contacts with people who spoke other languages, the English language evolved. One of the biggest influences was the Norman invasion of 1066 (from Normandy, France). This brought a lot of French words into the English language.
There are all kinds of books about the history of the English language. One fairly popular recent book is Our Marvelous Native Tongue by Robert Claiborne. You can probably also find an article about the history of the English language in an encyclopedia.