Following the battle of Bussaco on 27 September 1810 Wellington's heavily outnumbered troops began to withdraw towards Lisbon. By the evening of 9 October the British and Portuguese began to withdraw behind a line of defensive works that had been built to the north of Lisbon. These were not the rudimentary field works that the French anticipated, but an enormous network of forts, batteries and redoubts whose construction had been started the previous November - the Lines of Torres Vedras. This 30-mile-wide line utilised the area's natural defences, damming rivers, scarping hillsides, blocking roads and establishing forts upon almost all of the hills. This title describes its design, creation and effectiveness in the face of French attacks.

Ian Fletcher has established a reputation as a Napoleonic historian of the first rank, particularly on the British army in the Peninsular. He has been widely published and among his several titles for Osprey are Elite 52: 'Wellington's Foot Guards' and Campaign 65: 'Badajoz 1812'.

Bill Younghusband was born in 1936. He has been interested in all things military since childhood, an interest compounded through the reading of authors such as G. A. Henty. In 1954 he joined the Life Guards and saw service in Egypt and Cyprus. Bill is a respected military illustrator of many years' experience, and has illustrated numerous Osprey books on 18th- and 19th-century subjects. He is married, and lives in Ireland.