Oxford Dictionary of National Biography Online [U.K.]

The Oxford Dictionary of National Biography (DNB) is an "illustrated collection of more than 50,000 specially written biographies of the men and women from around the world who shaped all aspects of Britain's past ...". Coverage is from the earliest times to those who have been dead for 4 years or more.

This the online equivalent of the 60-volume print edition. It is updated 3 times per year.