  I describe the current status of our attempts to determine the age of the
oldest known stellar populations at high redshift, in the red mJy radio
galaxies 53W091 ($z = 1.55$) and 53W069 ($z = 1.43$). During the past year the
original conclusion of Dunlop et al. (1996) - that 53W091 is $>3$ Gyr old - has
been questioned from two, basically orthogonal directions. First, reports that
the near-infrared light from 53W091 is highly polarized have cast some doubt on
whether its red colour is genuinely due to an old population of stars. Second,
assuming that all the light is indeed due to stars, it has been claimed that
53W091 is in fact only 1-2 Gyr old. Here I present a preliminary analysis of
new infrared polarimetric observations of 53W091 which show that the first of
these criticisms can be rejected with very high confidence. I then explore why
different modellers have derived different ages for 53W091, and present new
model fits to the spectrum of 53W069 which demonstrate that different spectral
synthesis codes are certainly in good agreement that this galaxy is 3-4 Gyr
old. Finally I present a preliminary analysis of the morphologies and
scale-lengths of 53W091 and 53W069 as derived from new I-band WFPC2 HST images,
and compare the results with those for 3CR galaxies at comparable redshifts. I
conclude that the scalelengths and luminosities of radio galaxies at $z \simeq
1.5$ appear to scale together as would be predicted from the Kormendy relation
for low-redshift elliptical galaxies.
