Wendy Ayres-Bennett 
A History of the French Language Through Texts [PDF ebook] 

This new history of the French language allows the reader to see how the language has evolved for themselves. It combines texts and extracts with a readable and detailed commentary allowing the language to be viewed both synchronically and diachronically.
Core texts range from the ninth century to the present day highlight central features of the language, whilst a range of shorter texts illustrate particular points.
The inclusion of non-literary, as well as literary texts serves to illustrate some of the many varieties of French whether in legal, scientific, epistolatory, administrative or liturgical or in more popular domains, including attempts to represent spoken usage.
This is essential reading for the undergraduate student of French.