and a number of offices in Germany and abroad. Koberger's most famous publication was the Nuremberg Chronicle, published in 1493 in German and Latin editions. It contained an unprecedented 1,809 woodcut illustrations (albeit with many repeated uses of the same block) by the Wolgemut workshop. Dürer may have worked on some of these, as the work on the project began while he was with Wolgemut. Because Dürer left autobiographical writings and was widely known by his mid-twenties, his life is well documented in several sources. After a few years of school, Dürer learned the basics of goldsmithing and drawing from his father. Though his father wanted him to continue his training as a goldsmith, he showed such a precocious talent in drawing that he started as an apprentice to Michael Wolgemut at the age of fifteen in 1486. A self-portrait, a drawing in silverpoint, is dated 1484 (Albertina, Vienna) "when I was a child", as his later inscription says. The drawing is one of the earliest surviving children's drawings of any kind, and, as Dürer's Opus One, has helped define his oeuvre as deriving from, and always linked to, himself. Wolgemut was the leading artist in Nuremberg at the time, with a large workshop producing a variety of works of art, in particular woodcuts for books. Nuremberg was then an important and prosperous city, a centre for publishing and many luxury trades. It had strong links with Italy, especially Venice, a relatively short distance across the Alps. Wanderjahre and marriage (1490–1494) After completing his apprenticeship, Dürer followed the common German custom of taking Wanderjahre—in effect gap years—in which the apprentice learned skills from artists in other areas; Dürer was to spend about four years away. He left in 1490, possibly to work under Martin Schongauer, the leading engraver of Northern Europe, but who died shortly before Dürer's arrival at Colmar in 1492. It is unclear where Dürer travelled in the intervening period, though it is likely that he went to Frankfurt and the Netherlands. In Colmar, Dürer was welcomed by Schongauer's brothers, the goldsmiths Caspar and Paul and the painter Ludwig. Later that year, Dürer travelled to Basel to stay with another brother of Martin Schongauer, the goldsmith Georg. In 1493 Dürer went to Strasbourg, where he would have experienced the sculpture of Nikolaus Gerhaert. Dürer's first painted self-portrait (now in the Louvre) was painted at this time, probably to