http://www-groups.dcs.st-and.ac.uk:80/~history/
The MacTutor History of Mathematics is part of the Mathematical MacTutor system developed at the School of Mathematical and Computational Sciences of the University of St. Andrews for learning and experimenting with mathematics. The archive contains the biographies of more than 550 mathematicians. About 200 of these biographies are fairly detailed and most are accompanied by pictures of the mathematicians themselves.