  We present the Hamburg/RASS Catalogue (HRC) of optical identifications of
X-ray sources at high-galactic latitude. The HRC includes all X-ray sources
from the ROSAT Bright Source Catalogue (RASS-BSC) with galactic latitude |b| >=
30 degr and declination delta >= 0 degr. In this part of the sky covering ~10
000 deg^2 the RASS-BSC contains 5341 X-ray sources. For the optical
identification we used blue Schmidt prism and direct plates taken for the
northern hemisphere Hamburg Quasar Survey (HQS) which are now available in
digitized form. The limiting magnitudes are 18.5 and 20, respectively. For 82%
of the selected RASS-BSC an identification could be given. For the rest either
no counterpart was visible in the error circle or a plausible identification
was not possible. With ~42% AGN represent the largest group of X-ray emitters,
\~31% have a stellar counterpart, whereas galaxies and cluster of galaxies
comprise only ~4% and ~5%, respectively. In ~3% of the RASS-BSC sources no
object was visible on our blue direct plates within 40 arcsec around the X-ray
source position. The catalogue is used as a source for the selection of
(nearly) complete samples of the various classes of X-ray emitters.
