  This review addresses one of the important topics of current astrophysical
research, namely the role that supermassive black holes play in shaping the
morphology of their host galaxies. There is increasing evidence for the
presence of massive black holes at the centers of all galaxies and many efforts
are directed at understanding the processes that lead to their formation, the
duty cycle for the active phase and the question of the fueling mechanism.
Related issues are the epoch of formation of the supermassive black holes,
their time evolution and growth and the role they play in the early ionization
of the Universe. Considerable observational and theoretical work has been
carried out in this field over the last few years and I review some of the
recent key areas of progress.
