After 1900, as the potential advantages of wireless technology to the battlefield and for marine warfare became apparent, interested industrial organisations multiplied, keeping pace with the growth of the armies and navies that would soon apply their products to devastating effect. How twentieth-century warfare helped to speed the development of radio and electronic communications is worthy of recall. Warfare, however, can be seen as having had a more profound impact on this process over the past 100 years than almost any other driving force. Describing how this impact has led to improved systems of communications and a progressive diminution in size and weight of apparatus is one of the main objectives of this volume.