Picasso’s Erotic Code

A major new exhibition at the Gagosian Gallery tracks the affair between Picasso and Marie-Thérèse Walter, who became his mistress at 17, bore him a child, and committed suicide after his death, 50 years after they met. John Richardson tells the love story behind Walter’s encoded appearances in some of the 20th century’s most important artworks, including Picasso’s anti-war masterpiece, Guernica.