Known as Sir Anthony Blunt, KCVO, from 1956 to 1979, was a leading British art historian who in 1964, after being offered immunity from prosecution, confessed to having been a Soviet spy. A closely held secret for many years, his status was revealed publicly by Prime Minister Margaret Thatcher in November 1979, and he was stripped of his knighthood immediately thereafter. Blunt was Professor of the History of Art at the University of London, director of the Courtauld Institute of Art, and Surveyor of the Queen's Pictures. He was exposed as a member of the Cambridge Five, a group of spies working for the Soviet Union from some time in the 1930s to at least the early 1950s.
The author finds the characteristics in each period of his life time, and discusses about taking many example from his printings and illuminated book collection in Britain. I think the author's observation and criticism make sense and it is and will be the one of references of Blake's artworks, but I cannot deny the essay's composition is old-fashioned and the choice of examples are very small.