The initial numbered SF Masterworks series listed below was issued in paperback format between 1999 and 2009 by Orion Publishing's Millennium and Gollancz imprints, bringing together some of the best works of science fiction published during the twentieth century. SF Masterworks was a successor to the Gollancz Classic SF and VGSF Classics series issued between 1986 and 1990, and was itself superseded by an unnumbered paperback series in 2010.