  We investigate the old stellar populations of the 3CR radio galaxies at
redshift z ~ 1, using observations made with the Hubble Space Telescope and the
United Kingdom InfraRed Telescope. At radii r < 35 kpc, the infrared radial
intensity profiles of the galaxies follow de Vaucouleurs' law, whilst at larger
radii the galaxies show an excess of emission similar to that of low redshift
cD galaxies. The locus of the high redshift 3CR galaxies on the Kormendy
relation is investigated: passive evolution of the stellar populations is
required to account for their offset from the relation defined by low redshift
giant ellipticals and brightest cluster galaxies. The 3CR galaxies, on average,
possess larger characteristic radii than the low redshift brightest cluster
galaxies. Coupled with existing evidence, these results are strongly suggestive
that distant 3CR galaxies must be highly evolved systems, even at a redshift of
one, and lie at the centre of moderate to rich (proto-)clusters.
