The career of Englishman Sir George Cayley marked a turning point in the history of aviation. Cayley was the first to mount a well-conceived, systematic program of aeronautical research grounded in the scientific method. He conducted practical experiments in aerodynamics, published his findings in scientific journals, and performed flight tests with models and full-size gliders.

The most influential glider pioneer was Otto Lilienthal, a German engineer who began his aeronautical research in 1871 by studying bird flight. After nearly two decades of imaginative experimentation and research, he produced the best and most complete body of aerodynamic data up to that time. He published his results in Der Vogelflug als Grundlage der Fliegekunst (Birdflight as the Basis of Aviation) in 1889.

Following his program of data collection, Lilienthal constructed and tested a series of elegant, full-size gliders. Between 1891 and 1896 he made nearly 2,000 brief flights in 16 different glider designs based on his aerodynamic research.

On August 9, 1896, while flying one of his monoplane gliders, Lilienthal stalled and crashed. He died from his injuries the following day. The Wright brothers later cited his death as the point when their serious interest in flight research began.