A global overview is given of theoptical theory, historical development, current situation and future potential of reflecting telescope systems. This first volume covers basic design theory, providing the reader with the most complete account available. It is thus a source book for the astronomical community and the optical industry. The author's approach is morphological, with strong emphasis on the historial development. The book is richly illustrated including spot-diagrams analysing special systems in modern form. Since all basic forms of reflecting telescope systems are known and the theory is largely completed, this volume should retain long-term validity and interest.