Automatic control, particularly the application of feedback, has been fundamental to the devel- opment of automation. Its origins lie in the level control, water clocks, and pneumatics/hydraulics of the ancient world. From the 17th century on- wards, systems were designed for temperature control, the mechanical control of mills, and the regulation of steam engines. During the 19th cen- tury it became increasingly clear that feedback systems were prone to instability. A stability cri- terion was derived independently towards the end of the century by Routh in England and Hur- witz in Switzerland. The 19th century, too, saw the development of servomechanisms, first for ship steering and later for stabilization and autopilots. The invention of aircraft added (literally) a new dimension to the problem. Minorsky\\’s theoreti- cal analysis of ship control in the 1920s clarified the nature of three-term control, also being used for process applications by the 1930s. Based on servo and communications engineering devel- opments of the 1930s, and driven by the need for high-performance gun control systems, the coherent body of theory known as classical con- trol emerged during and just after WWII in the US, UK and elsewhere, as did cybernetics ideas. Meanwhile, an alternative approach to dynamic modelling had been developed in the USSR based on the approaches of Poincaré and Lyapunov.