Alexander Gilchrist's Life of William Blake, "Pictor Ignotus" (1863) effected a critical reassessment far beyond that which most biographies have ever occasioned. The book's subtitle, which means "unknown painter," was only a slight exaggeration. Blake may not have been completely unknown, but it was only with the publication of Gilchrist's biography that, as G. E. Bentley, Jr., says, "Blake at last took his place in literary and artistic history as one of the great figures of the Romantic movement." Gilchrist's Life of William Blake began the scholarly and critical interest in Blake that has continued unabated for more than a century. Naturally, there are aspects of the book that now appear inadequate and dated; yet those limitations have only become evident because of later work that Gilchrist himself inspired and made possible.

The sixth of seven children, Gilchrist was born on 25 April 1828 in London. His father, James Gilchrist, the...