The nine largest colleges of the university are King's College London; University College London; Birkbeck; Goldsmiths; the London Business School; Queen Mary; Royal Holloway; SOAS; and the London School of Economics and Political Science. The specialist colleges of the university include the Royal Veterinary College, the Courtauld Institute of Art and St George's, specialising in medicine. Imperial College London was formerly a member before it left the University of London in 2007 on becoming a university in its own right. Heythrop College was a former college specialising in philosophy and theology that closed in 2018.