Roger Apéry (November 14, 1916 December 18, 1994) was a Greek-French mathematician most remembered for Apéry's theorem, that (3) is an irrational number where denotes the Riemann zeta function. Apéry was born in Rouen in 1916 to a French mother and Greek father. After studies at the École Normale Supérieure (interrupted by a year as prisoner of war during World War II) he was appointed Lecturer at Rennes. In 1949 he was appointed Professor at the University of Caen where he remained until his retirement. He died after a long illness in Caen in 1994. In 1979 he published an unexpected proof of the irrationality of (3), which is the sum of the inverses of the cubes of the positive integers. An indication of the difficulty is that the corresponding problem for other odd powers remains unsolved.