A very rare, revealing and valuable document from that genius of military engineering, Col. John T. Jones R.E. Jones, author of the thee volume Peninsula War classic ‘Sieges in Spain” (also published by the Naval and Military Press), privately printed and circulated these memoranda which he had withdrawn from the second edition of his ‘Sieges’ because he considered the material still too secret and sensitive for general release. The subject is the famous ‘Lines of Torres Vedras’ the vast system of defensive earthworks and fortifications thrown up on Wellington’s orders to guard the Lisbon peninsula as he retreated into Portugal before the pursuing French forces under Marshal Massena after the battle of Talavera in 1810. The lines performed their purpose beyond Wellington’s wildest dreams – having denuded the country in fron of them of anything that could sustain the French, he withdrew behind the safety of the defences and waited. Unable to maintain his army or assault the massive fortifications, Massena was forced to retreat. In retrospect the Lines of Torres Vedras are seen as not only a wonder of military engineering, but the watershed that turned the course of the whole Peninsula War. The memoranda are accompanied by a selection of detailed and beautiful endpaper diagrams.