The pillboxes of Britain & Ireland are among the most important military structures employed in the history of the defence of these islands. This work presents the first thorough study & classification of pillboxes & related structures including selection posts Seagull & concrete trenches gun-houses & turrets battle headquarters & spigot-mortar emplacements. The author traces the use of small free-standing defence structures from ancient times to the present placing the pillbox within a historical continuum & identifying its course of development. The work also presents a typology of British & Irish pillboxes through a catalogue of known types & individual examples & examines their tactical employment in the landscape. Mike Osbourne has been involved in the recording of defence structures for over 30 years & was co-ordinator of the Defence of Britain Project in the eastern counties. He is also the author of Defending Britain: Twentieth-Century Military Structures in the Landscape also published by The History Press.