During the last twenty-six years of his life (1550-1576) the artist worked mainly for Philip II and as a portrait-painter. He became more self-critical, an insatiable perfectionist, keeping some pictures in his studio for ten years, never wearying of returning to them and retouching them, constantly adding new expressions at once more refined, concise, and subtle. He also finished off many copies of earlier works of his by his pupils, giving rise to many problems of attribution and priority among versions of his works, which were also very widely copied and faked outside his studio, during his lifetime and afterwards. Titian Vecelli, undeniably the greatest Venetian painter of the Renaissance, leaps into the full light of the movement. To be sure he appears full-grown, as Venus is said to have done when she appeared above the foam in the waters of Cythera, or Pallas Athene when she12 sprang from the brain of Zeus, but happily he was destined to live to a great age.