First edition, edition limited to 1000 copies, 2 volumes, 4to, titles printed in red, collotype frontispiece in volume 2, collotype and line facsimiles, illustrations, maps and plans after Lawrence in the text, many full-page, some colour-printed. 2 folding maps after H. Pirie-Gordon contained in a loosely-inserted envelope, original red crushed half morocco over cloth by Sangorski & Sutcliffe, spines gilt, top edge gilt, others uncut, slight fade to spines else a fine set. Lawrence's classic text on Crusader castles and their relation to the military architecture of the West, written whilst still an Oxford undergraduate in 1910. At the end of the nineteenth century, it was generally assumed that these castles were the prototype for the massive buildings erected in Northern France and England in the twelfth and thirteenth centuries. Lawrence opposed this view: unlike most earlier writers on the subject, he was already familiar with castles in England, Wales, France and Syria as a result of a series of expeditions made on bicycle or foot, culminating in 1909 in a three-and-a-half month walking tour of the Levant. Although his thesis was to guarantee him a first-class degree in Modern History, its impact on scholarship was slower to take effect. The typescript remained virtually unknown until 1936, a year after the author's death, when it appeared in the present limited edition. O'Brien A188 & A189.