There is very little about Picasso that John Richardson, his longtime biographer, doesn’t already know. As a friend of Picasso’s during the 1950s, while the artist was living in the south of France, Mr. Richardson saw more than most.

He can reveal juicy snippets about Picasso’s sexual escapades and recall many of his personal quirks: How Picasso would rub a concoction of oil heated with sticks of lavender into his scalp to make his hair grow; his passion for salt cod purée; his loathing of classical music. Mr. Richardson can also describe in riveting detail Picasso’s methods of painting, sculpting and drawing.