After almost 400 years, the well-known long-lost painting Leda and the Swan by the Rudophine master Joseph Heintz has resurfaced. It is an artwork, which was most respected by Heintz's contemporaries and was considered lost for good. Three preparatory drawings for this painting are known, one of them owned by the National Gallery in Prague. Joseph Heintz the Elder (1564, Basel - 1609, Prague) was a prominent artist and court painter of Emperor Rudolph II in Prague but he also made a name for himself in Augsburg, Germany. When his peak artwork Leda and the Swan was re-discovered, three art institutions - the Kunstsammlungen und Museen Augsburg, the National Gallery in Prague and the Kunsthistorisches Museum in Vienna, Austria - have agreed to organize separate small exhibitions, respectively, on the theme of this painting. One was held in the spring in Augsburg, where Heintz had worked as a painter, inventor of prints and also architect. Another exhibition will be held in 2016 in Vienna, where a large part of Rudolph II's imperial collections have survived. We prepare our exhibition in the autumn in Prague, where Heintz worked in the imperial services. The small exhibition in Prague will present Joseph Heintz the Elder as an artist through his selected artworks. The National Gallery in Prague will display his well-known painting Leda and the Swan (it will be loaned from a collection abroad) with its preparatory drawing as well as other paintings, drawings and graphic sheets. We will also offer more stories linked with the painting's theme, the classical myth about Leda, the beautiful queen of Sparta, and her encounter with Jupiter, the highest god on Mount Olympus.