World Encyclopedia of Amphibious Warfare Vessels: An illustrated history of modern amphibious warfare

Wars are decided definitively through the occupation of an enemy's territory. This is a task for military forces, which may have to be transported by sea. In extreme cases, as in the Pacific War of 1941-45, this may involve trans-oceanic passages. Thus is created the conflicting requirement for ships sufficiently large to undertake lengthy voyages, together with craft small enough to put an army and its equipment on to a beach that may be defended by a determined enemy.,
In the sailing navy...