Pierre de Fermat

Timeline

1. 1601–1631Beaumont-de-Lomagne · LanguedocBorn in Beaumont-de-Lomagne in Gascony to a well-off family. He first studied in Bordeaux, then went to the University of Orléans to study law, received his bachelor of laws in 1631, and was registered as a lawyer at the Parlement of Toulouse. From an early age he took a keen interest in ancient Greek number theory and arithmetic problems, beginning mathematical research alongside his judicial duties.
2. 1631–1651Toulouse · LanguedocFrom 1631 he practiced in Toulouse and rose to become royal counsel, and in 1648 chief speaker of the Parlement. In his spare time he corresponded with Mersenne, Descartes, Huygens, and other European scholars, proposing many original results in number theory, geometry, and optics, including statements of Fermat's little theorem and the law of refraction, but because he rarely published complete proofs they long circulated only in manuscripts and letters.
3. 1651–1660Toulouse · LanguedocIn 1654 he corresponded with Pascal on the division of stakes, laying the foundation of probability theory; around the same time he wrote his famous conjecture of Fermat's Last Theorem in the margin of his copy of Arithmetica. In 1657 he proposed a method for solving Pell's equation of the form x²−Ny²=1, and continued studying infinitesimal methods and extremum problems; much of his work was published posthumously by his son Clément Samuel.
4. 1660–1665Castres · LanguedocIn the 1660s he gradually withdrew from heavy official duties while continuing mathematical correspondence and organizing his manuscripts. He died of illness at Castres on 12 January 1665, aged sixty-three; in 1679 his son published Opera Matematica, making a large body of number-theoretic and geometric results available to posterity and becoming a lasting treasure trove for later mathematicians.