Pierre de Fermat was a French mathematician who lived in France, Europe in the 17th century. Fermat was given credit for the development of calculus and the founder of the modern theory of numbers. Upon his death, Fermat left behind a note claiming to have discovered "remarkable proof" for what became known as Fermat's last theorem.
His theorem was not proved until 1995 by Andrew Wiles, though many others, including Jean-Luc Picard, Tobin and Jadzia Dax, worked on more original approaches to the proof since. (TNG: "The Royale"; DS9: "Facets")