  I review our knowledge of the properties of the host galaxies of radio-loud
and radio-quiet quasars, both in comparison to each other and in the context of
the general galaxy population. It is now clear that the hosts of radio-loud and
radio-quiet quasars with M_V < -23.5 are virtually all massive elliptical
galaxies. The masses of these spheroids are as expected given the relationship
between black-hole and spheroid mass found for nearby quiescent galaxies, as is
the growing prevalence of disc components in the hosts of progressively fainter
AGN. There is also now compelling evidence that quasar hosts are practically
indistinguishable from normal ellipticals, both in their basic structural
parameters and in the old age of their dominant stellar populations; at low z
the nuclear activity is not associated with the formation of a significant
fraction of the host galaxy. While the long-held view that quasar radio power
might be a simple function of host morphology is now dead and buried, I argue
that host-galaxy studies may yet play a crucial role in resolving the
long-standing problem of the origin of radio loudness. Specifically there is
growing evidence that radio-loud objects are powered by more massive black
holes accreting at lower efficiency than their radio-quiet couterparts of
comparable optical output. A black-hole mass > 10^9 solar masses appears to be
a necessary (although perhaps not sufficient) condition for the production of
radio jets of sufficient power to produce an FRII radio source within a massive
galaxy halo.
