Pierre de Fermat, a lawyer and jurist by profession, made major contributions to every field of mathematics that existed in the seventeenth century. He developed the principles of analytic geometry independently from his contemporary René Descartes . Fermat is regarded by some mathematicians as the inventor of differential calculus. He created modern number theory, and, together with Blaise Pascal, developed the theory of probability. Fermat's wide range of accomplishments is especially remarkable considering that mathematics was for him only a hobby.

Pierre Fermat was baptized and most likely born on August 20, 1601, in Beaumont-de-Lomagne. His father, Dominique Fermat, was bourgeois second consul of Beaumont-de-Lomagne and a prosperous leather merchant. His mother, Claire de Long, came from a prominent family of parliamentary lawyers. Fermat had three siblings, a brother, Clement, and two sisters, Louise and Marie. His early education was most likely received at the Franciscan monastery in Beaumont. During...