THE commission must have been challenging, even for a master of Titian’s calibre. Someone, possibly Philip II of Spain or Venetian sculptor Danese Cattaneo, had asked the Italian artist to paint a portrait of Hürrem (or Roxelana, as she was known in Europe), wife of the Ottoman Sultan, Suleiman I. Titian had never set foot in Istanbul, but that wasn’t in itself an issue—he had painted, based only on a medal or a small effigy, several portraits of Suleiman, including one for the Duke of Mantua that the city’s ambassador, Benedetto Agnello, called ‘so similar …that it seems the very Turk alive’. Much trickier was the fact that few people knew what the secluded Hürrem really looked like. Nonetheless, Titian and his workshop, perhaps aided by their imaginations, managed to…