  We present a study of the galaxies found in the Hubble Deep Field. A high
proportion of HDF galaxies are undergoing a strong episode of star formation,
as evidenced by their very blue colours. A wide range of morphological types is
found, with a high proportion of peculiar and merger morphologies. Fitting the
multiband spectra with redshifted SEDs of galaxy types E to HII, we predict the
spectral types and redshifts of galaxies detected in the HDF. We find a median
redshift of 1.6, with $68\%$ having $z > 1$ and $31\%$ with $z >2$. The I-band
absolute magnitude distributions as a function of galaxy types show a plausible
trend of decreasing luminosity towards later types. The derived I-band
luminosity function agrees well with that from the Canada-France survey (Lilly
et al 1996) for $z < 1$ and shows strong luminosity evolution at $M_I < -21$
for $1 < z < 3$, comparable to the rate seen in quasars and starburst galaxies.
We have predicted infrared and submillimetre fluxes assuming most of the
galaxies are undergoing a strong starburst. Several planned space-borne and
ground-based deep surveys are capable of detecting interesting numbers of HDF
galaxies.
