Aircraft History. Initial period. - a book about the early period of aviation development, from the first experiments and projects to airplanes during the First World War. Man has been trying to get airborne since ancient times. In the Middle Ages, designs of devices powered by human muscle power appeared. In the 19th century, they tried to install a steam engine on the aircraft. Only the advent of a compact and lightweight internal combustion engine in the twentieth century finally allowed the creation of a successful aircraft project. The book examines many aircraft designs built before 1919. This book is a continuation of the work "History of aircraft. The initial period," published in 1995. The paths of development of aircraft of various countries from the end of the First World War to 1945 are covered in detail. The study used materials from libraries and archives in Russia, the USA, and Germany.