There is a vivid moment in Farah Karim-Cooper’s new book where she reflects on the image of the nation’s pre-eminent playwright – how unfathomable he has seemed to artists and how his face has been conjured from a historical blur. She compares portraits and discerns a marked shift in the 18th century when he seems to become “more beautiful, symmetrical, and whiter in complexion”. If visual art has hitherto seemed like a peripheral detail in the appraisal of his work, Karim-Cooper, a professor of Shakespeare studies, connects this paled image to a metaphorical whitewashing: the man we celebrate today is...