  We have extended our previous analysis of morphologically selected elliptical
and S0 galaxies in the Hubble Deep Field (HDF) North to include HST data in the
HDF South and the HDFS-NICMOS areas. Our final sample amounts to 69 E/S0
galaxies with $K<20.15$ over an area of 11 square arcmins. Although a
moderately small number over a modest sky area, this sample benefits of the
best imaging and photometric data available on high-redshift galaxies.
Multi-waveband photometry allows us to estimate with good accuracy the
redshifts for the majority of these galaxies which lack a spectroscopic
measure. We confirm our previous findings that massive E/S0s tend to disappear
from flux-limited samples at $z>1.4$. This adds to the evidence that the
rest-frame colours and SEDs of the numerous objects found at $0.8<z<1.2$ are
inconsistent with a very high redshift of formation for the bulk of stars,
while they are better consistent with protracted (either continuous or
episodic) star-formation down to $z \le 1$. These results based on high-quality
imaging on a small field can be complemented with data from colour-selected
EROs on much larger sky areas: our claimed demise of E/S0s going from $z=1$ to
$z=1.5$ is paralleled by a similarly fast decrease in the areal density of EROs
when the colour limit is changed from $(R-K)=5$ to $(R-K)=6$ (corresponding to
$z\simeq 1$ and $z\simeq 1.3$ respectively). Altogether, the redshift interval
from 1 to 2 seems to correspond to a very active phase for the assembly of
massive E/S0 galaxies in the field, and also probably one where a substantial
fraction of their stars are formed.
