Giovanni Battista Tiepolo was the most famous Italian painter of the 18th century. His greatest achievement was the decoration of two rooms in the palace, or Residenz, of Carl Philipp von Greiffenklau, prince-bishop of Würzburg, carried out between 1751 and 1753. This painting is the oil sketch presented by Tiepolo on April 20, 1752, for the vast fresco over the staircase of the palace. It shows Apollo about to embark on his daily course across the sky; the deities around him symbolize the planets, and the allegorical figures on the cornice represent the four continents of the world. Numerous changes were made between the oil sketch and the fresco, but this painting shares with the completed ceiling the feeling for airy space, sun-washed colours, and the prodigious inventiveness for which Tiepolo is admired.