This is a new edition (the first since 1936) of the classic text on Crusader castles and their relation to Western military architecture written by T.E. Lawrence in 1910. This volume reproduces Lawrence's text, drawings, and photographs; provides a new introduction, critical notes, and index; and reassesses in light of recent scholarship Lawrence's controversial claim that Crusader castles of the 12th century owed more to castles in the West than to anything the Franks found in the East, and that western military architecture absorbed little or nothing from the Orient before the 12th century.