He is internationally renowned, and has been claimed to be the richest living artist to date. During the 1990s his career was closely linked with the collector Charles Saatchi, but increasing frictions came to a head in 2003 and the relationship ended. Death is a central theme in his works. He became famous for a series of artworks in which dead animals (including a shark, a sheep and a cow) were preserved sometimes being dissected, in formaldehyde. The Physical Impossibility of Death in the Mind of Someone Living, a 14-foot (4.3 m) tiger shark immersed in formaldehyde in a vitrine became the iconic work of British art in the 1990s, and the symbol of Britain art worldwide. He has also made “spin paintings,” created on a spinning circular surface, and “spot paintings“, which are rows of randomly-colored circles.