A previously unknown portrait by Pablo Picasso of one of his lovers was revealed on Thursday after being put up for sale at auction in Paris with a reserve price of eight million euros ($9.5 million).

Between the mid-1940s and early 1970s, Pablo Picasso was involved with the Madoura pottery workshop and the printmaking studio of Hidalgo Arnéra in Vallauris, France. The result was a revelatory ...