The term pole, in the sense used in projective geometry, was first introduced in 1810 by the French mathematician Servois, and the corresponding term polar by Gergonne three years later. The idea of poles and polars was later elaborated by Gergonne and Poncelet into a regular geometry method, out of which grew the elegant principle of duality of projective geometry (see Problem Study 9.12). Projective geometry was freed of any metrical basis by Staudt in 1847.