Cornelis Sebille Roos, by A. de Lelie, 1815. Cornelis Roos (1754-1820) was the first director of the Nationale Konstgallerij - the national artgallery - which opened to the public in 1800. This museum, the forerunner of today's Rijksmuseum, was housed in Huis ten Bosch in The Hague. It included paintings and objects from the collections assembled by successive stadholders.