  A catalogue of 239 ultra-compact HII regions (UCHIIs) found in the CORNISH
survey at 5 GHz and 1.5" resolution in the region $10^{\circ} < l < 65^{\circ},
~|b| < 1^{\circ}$ is presented. This is the largest complete and well-selected
sample of UCHIIs to date and provides the opportunity to explore the global and
individual properties of this key state in massive star formation at multiple
wavelengths. The nature of the candidates was validated, based on observational
properties and calculated spectral indices, and the analysis is presented in
this work. The physical sizes, luminosities and other physical properties were
computed by utilising literature distances or calculating the distances
whenever a value was not available. The near- and mid-infrared extended source
fluxes were measured and the extinctions towards the UCHIIs were computed. The
new results were combined with available data at longer wavelengths and the
spectral energy distributions (SEDs) were reconstructed for 177 UCHIIs. The
bolometric luminosities obtained from SED fitting are presented. By comparing
the radio flux densities to previous observational epochs, we find about 5% of
the sources appear to be time variable. This first high-resolution area survey
of the Galactic plane shows that the total number of UCHIIs in the Galaxy is ~
750 - a factor of 3-4 fewer than found in previous large area radio surveys. It
will form the basis for future tests of models of massive star formation.
