Who developed the first known principles of flight?

Leonardo da Vinci is recognized for laying the groundwork for the principles of flight through his extensive studies of birds and his innovative designs for flying machines. His observations of the mechanics of bird flight and his sketches of devices, such as the ornithopter, reflected an early understanding of aerodynamics and lift, which are fundamental to flight. Da Vinci was ahead of his time, documenting concepts of gliding and controlled flight that were not practically realized until centuries later.

The contributions of other figures, while significant in the history of aviation, came after da Vinci's ideas. For example, Otto Lilienthal is known for making the first recorded controlled flights with a heavier-than-air aircraft in the late 19th century, while the Wright brothers achieved the first powered flight in the early 20th century. Thaddeus S. C. Lowe contributed to aeronautics through his work with balloons and was instrumental during the Civil War, but his contributions focused more on airships than the fundamental principles of flight as developed by da Vinci.