This year has brought the centenary of Dirichlet’s death (5 May 1859), and it is fitting that we should recall some of his achievements and his part in the development of mathematics.

Gustav Peter Lejeune Dirichlet was born on 13 February .1805, and was the son of the postmaster at D?ren, near Cologne. Among the schools he attended Was a Gymnasium at Cologne, Where one of his teachers was the physicist Ohm. When the time came for University study in .1822, Dirichlet persuaded his parents to let him go to Paris, which Was then the world centre of mathematics. Laplace and Legendre Were still alive and active, Fourier Was at the height of his career, With a group of brilliant young men round him, and Cauchy had already begun his massive development of the theory of flmctions.