  We have determined the central velocity dispersion and surface brightness
profiles for a sample of powerful radio galaxies in the redshift range
0.06<z<0.31, which were selected on the basis of their young radio source. The
optical hosts follow the fundamental plane of elliptical galaxies, showing that
young radio sources reside in normal ellipticals, as do other types of radio
galaxies. As young radio sources are relatively straightforward to select and
the contributions of the AGN light to the optical spectra are minimal, these
objects can readily be used to study the evolution of the fundamental plane of
elliptical galaxies out to z=1, independently of optical selection effects. The
black hole masses of the objects in our sample have been determined using the
tight empirical relation of M_bh with central velocity dispersion, and for
literature samples of classical radio galaxies and optically selected
ellipticals. Only the optically selected in-active galaxies are found to
exhibit a correlation between M_bh and radio luminosity. In contrast, the radio
powers of the AGN in the samples do not correlate with M_bh at all, with
objects at a given black hole mass ranging over 7 orders of magnitude in radio
power. We have been able to tie in the population of powerful radio sources
with its parent population of in-active elliptical galaxies: the local black
hole mass function has been determined, which was combined with the fraction of
radio-loud black holes as function of M_bh, as determined from the optically
selected galaxy sample, to derive the local volume-density of radio galaxies
and the distribution of their black hole masses. These are shown to be
consistent with the local radio luminosity function and the distribution of
black hole masses in the radio selected samples [ABBREVIATED]
