Parker's life of Milton has long been accepted as one of the great literary biographies of the twentieth century, a unique accomplishment of scholarship based on a vast range of documentary evidence. Originally published in 1968, the biography was immediately acclaimed as `indispensable', `authoritative', as well as `controversial', and Parker himself was described in The Review of English Studies as `a living library and a walking museum'. Since the first edition was published, our understanding of seventeenth-century history has been fundamentally reshaped by historians and literary scholars. Gordon Campbell's revised edition of the commentary includes supplementary notes which record recent findings with biographical implications, as well as the suggested resolutions to some of the questions raised by Parker's original text, such as the dating of Samson Agonistes and Milton's History of Britain.