Now revised, The Story of English (1986) by Robert McCrum (http://en.wikipedia.org/wiki/Robert_McCrum) was the first book to tell the whole story of the English language for a popular audience. It presents a stimulating and comprehensive record of spoken and written English, from its Anglo-Saxon origins some two thousand years ago to the present day, when English is the dominant language of commerce and culture with more than one billion speakers around the world.
From Cockney, Scouse, and Scots to Gulla, Singlish, Franglais, and the latest African American slang, this sweeping history of the English language is a superb introduction for anyone who wants to know more about our common tongue. Available at http://www.amazon.co.uk/The-Story-English-Robert-McCrum/dp/0571275087/ref=tmm_pap_title_0?ie=UTF8&qid=1389523887&sr=8-1
Complement this with Melvyn Bragg’s The Adventure of English (2003) (http://www.amazon.co.uk/The-Adventure-English-Melvyn-Bragg/dp/0340829931/ref=tmm_pap_title_0?ie=UTF8&qid=1389524293&sr=8-1)
496 pages in Faber & Faber paperback edition
ISBN 978-0571275083
Robert McCrum