Wellington's Operations in the Peninsula (1808-1814) by Lewis William George Butler and Arthur Wellesley Wellington. 2 vols. Published by T. F. Unwin, 1904:

Vol 1:
http://books.google.com/books?id=mNT8HVHZDa4C

Vol 2:
http://books.google.com/books?id=WegAAAAAMAAJ