Giorgione can rightly be called the founding father of sixteenth-century Venetian painting, even though his life and work are cloaked in numerous mysteries. Named Zorzi in Venetian dialect, the artist was probably born in Castelfranco Veneto around 1477 or 1478. He is first documented between August 1507 and January 1508, when he produced a painting for the Sala dell'Udienza in the Doge's Palace, which had already been lost by the end of the sixteenth century. In December 1508 Giorgione was paid for his painting of the facade of the Fondaco de' Tedeschi, the establishment of the German merchants in Venice, of which only a fragment in the Ca' d'Oro survives in addition to descriptions and late engravings after individual figures. In October 1510 Isabella d'Este, Marchese of Mantua, asked her agents in Venice to purchase a Giorgione night piece ("una nocte") for her. Her confidant replied that the artist had recently died of the plague, and that there were no works of his, including his two known night pieces, for sale. None of the paintings attributed to Giorgione is signed or dated, and none can be identified as works mentioned in the documents. Only two have dates and inscriptions in another hand on the back that identify them as the work of Giorgione: the so-called 'Laura' in Vienna's Kunsthistorisches Museum (1506) and the 'Portrait of a Man' in the San Diego Museum of Art (1506 or 1510). The attributions of other surviving works to Giorgione are based above all on Venetian sources from the sixteenth century, all of which date from only after the artist's death. In this way the 'Storm' in Venice's Accademia and the 'Boy with an Arrow' and 'Three Philosophers' in the Kunsthistorisches Museum in Vienna are assured for the painter, and a series of others, such as the 'Sleeping Venus' in Dresden and the Braunschweig fragment of a David with the head of Goliath are in all likelihood to be claimed for him as well. Yet the fact that these early sources identify the 'Three Philosophers' and the Dresden 'Venus' as unfinished works that were completed by Sebastiano del Piombo and Titian makes it difficult to distinguish the peculiarities of Giorgione's signature from those of his younger contemporaries, some of whom were employed in his workshop. The dearth of dated works or works that can be securely dated from external clues also makes the chronological sequence of his oeuvre highly problematic. In the barely fifteen years of his activity, Giorgione revolutionised Venetian painting. Unlike the older generation of artists around Giovanni Bellini, Giorgione worked, according to Vasari, without preliminary drawings, instead structuring his motifs in colour directly on a medium often made of cloth, using loose brushstrokes and pastose highlights. As a result, the works often show radical changes made while they were being painted. In addition to his activity as a fresco painter, Giorgione specialised in small-format paintings that he produced for art-loving collectors who were likely familiar with their mythological or literary sources. Interpreting some of their content can be difficult to this day, for Giorgione clearly cared more about the poetic atmosphere of his compositions than about clearly describing the event depicted.