This volume contains the proceedings of the 33rd Herstmonceux Conference, the latest in a venerable series initiated by the Royal Greenwich Observatory in its former home at Herstmonceux Castle. It is the second conference in the series to have been jointly organized by the RGO and the Institute of Astronomy at Cambridge. However, it also marks a beginning. Both the timing and the subject matter of the meeting in Cambridge were co-ordinated with a companion conference in Paris. Together, the two meetings marked the inauguration of the European Association for Research in Astronomy. This grouping links together the Institute of Astronomy, the Institut d'Astrophysique de Paris, and Leiden Observatory with the intention of encouraging scientific exchanges between the three laboratories and enhancing their collaborative research activities. The Paris conference, entitled First Light in the Universe: Stars or QSO's, took place during July 7–11, 1992 at the Institut d'Astrophysique and was concerned with the cosmological evolution of galaxies and quasars, with particular emphasis on the alternative rôles played by starbursts and active galactic nuclei. In Cambridge, our aim was to focus in detail on the sources which power active galactic nuclei themselves.

Active galactic nuclei (AGN) are undoubtedly the most spectacular objects known to astronomy yet the nature of the fundamental power source remains elusive, despite many years of intensive research. Indeed, the somewhat ambiguous conference title reflects the fact that the conventional black hole–accretion disk paradigm is now being strongly challenged by the starburst hypothesis.