The fourth volume of the history of air warfare-focusing on the war at sea and the Western Front This outstanding, multi-volume examination of aerial warfare during the First World War from the perspective of British air forces continues in volume four with accounts of two different theatres. As the war progressed Germany increasingly invested resources in the expansion of its submarine fleet. German surface warships were comparatively ineffective strategically, since Germany is poorly placed geographically as regards access to the seaways. Allied surface fleets meanwhile remained powerful with free access to supplies and ports across the globe. Escorted merchant ships carrying essential war materiel and other goods continued to dock in and depart from the British Isles. The German solution to disrupt seaborne traffic and so compromise the effectiveness of Allied armies in the field initially proved to be brutally effective and measures to defeat the undersea menace of the U-Boats were of paramount importance. The work of the RFC and the RNAS in countering the scourge of the submarine and other naval threats is described here in thorough detail. The second part of this volume continues the examination of the war in the air as it was fought over the trenches of the Western Front. The war had reached a point of stalemate on the ground which made its aggressive prosecution in the skies essential and this volume, which covers the period from the Battle of Messines to the German Spring Offensive of 1918, includes many riveting accounts of aerial combat. Leonaur editions are newly typeset and are not facsimiles; each title is available in softcover and hardback with dustjacket.