This study details the preparation, planning and execution of the
invasion of Portugal in 1810 by the French Armée de Portugal under
Marshal Massena, and the defensive measures taken by the British and
their Portuguese and Spanish allies. It also covers the practice of all
armies involved during this campaign, working from original sources.
These sources provide a different interpretation of some key aspects of
the campaign to those which are generally accepted. The work focusses on
the strategic, operational, and tactical planning undertaken by both
sides in preparation for the invasion, and the actual progress of the
campaign. A narrative of the battles and sieges, with analysis at the
tactical-level, also brings out the differences in planning and
intelligence gathering.
This particular campaign is important as it has attracted little
attention from historians, and was crucial as a turning point in the
Peninsular War. This was the last time that Portugal was invaded by the
French during the Peninsular War, and the allies' handling of the
campaign contrasted sharply with that of the French. Its success also
gave Wellington political security against the 'croakers' back in
England. The research demonstrates the difficulties both armies had in
prosecuting their plans during the campaign, and highlights the stark
differences in the approach taken by each commander.