(born 1953). In June 1993 in England, at a small conference of mathematicians at the Isaac Newton Institute, Cambridge, Andrew Wiles dropped a historic bombshell. He had solved one of mathematics’ oldest mysteries, Fermat’s last theorem. The Princeton University professor’s seven-year attack on the 350-year-old problem, one that many mathematicians had declared unsolvable, ended when, on the third and final day of his lecture on elliptic curves, he announced his proof of the theorem. In December, during review of the 200-page proof for publication, a small snag was found, but the pervasive feeling among Wiles’s peers was that he had indeed pulled it off. Indeed, after some months of additional work, the snag was overcome and the proof was accepted as modified.

Andrew John Wiles was born on April 11, 1953, in Cambridge. He had dreamed of solving Fermat’s last theorem from the age of 10, when he first encountered the problem in a book. In fact, he credited the problem with inspiring his interest in mathematics and leading him to his life’s work as a number theorist. Wiles, who was also married to a mathematician (they used to recite the decimal places of pi to each other), studied mathematics at Clare College, Cambridge, where he earned a Master of Arts in 1977 and a Ph.D. in 1980. He joined the mathematics faculty of Princeton University in 1980.

Fermat’s last theorem, so called because it was the only remaining theorem of the 17th-century French mathematician Pierre de Fermat that had been neither proved nor disproved, dates to 1637. While reading a copy of the *Arithmetica* by the ancient Greek mathematician Diophantus, Fermat scribbled his theorem in the book’s margin along with the note that he had a “remarkable proof” but that “the margin is too small to contain it.” So began a mystery that stymied the world’s greatest mathematical minds for the next three centuries. Particularly vexing for would-be solvers was the theorem’s simplicity. It states that there are no positive integer solutions to *x ^{n} + y^{n}* =

*z*when

^{n}*n*is greater than two. Fermat himself eventually found a space large enough to write a proof for

*n*= 4, and others elaborated proofs for specific cases of

*n.*A universal solution, however, remained elusive until Wiles made his June announcement.

The heart of Wiles’s proof relies upon the Taniyama-Weil conjecture, a difficult problem in number theory dealing with the nature of elliptic curves (equations of the form *y ^{2}* =

*x*+

^{3}*ax*+

*b,*in which

*a*and

*b*are constants). In 1986 Kenneth A. Ribet of the University of California at Berkeley showed that if the conjecture could be proved, a proof of Fermat’s theorem would follow. Inspired by Ribet’s work, Wiles labored privately and secretly in the attic office of his Princeton home for seven years. By May 1993 he had succeeded in solving a special case of the Taniyama-Weil conjecture—enough to prove Fermat’s last theorem—and he quickly signed on to speak at the Cambridge conference. After the first day’s lecture, speculation swelled that Wiles had a solution to Fermat’s problem. On the third day, when Wiles finally revealed the proof, he received a standing ovation from the audience.