  We present the final band-merged ELAIS catalogue at 6.7, 15, 90, and 175
$\mu$m, and the associated data at u,g,r,i,z,J,H,K, and 20cm. The origin of the
survey, infrared and radio observations, data-reduction and optical
identifications are briefly reviewed, and a summary of the area covered, and
completeness limit for each infrared band is given. A detailed discussion of
the band-merging and optical association strategy is given. The total
catalogues consists of 2860 sources. For extragalactic sources observed in 3 or
more infrared bands, colour-colour diagrams are presented and discussed in
terms of the contributing infrared populations. Spectral energy distributions
are shown for selected sources and compared with cirrus, M82 and Arp220
starburst, and AGN dust torus models.
  Spectroscopic redshifts are tabulated, where available. For the N1 and N2
areas, the INT ugriz Wide Field Survey, permits photometric redshifts to be
estimated for galaxies and quasars. These agree well with the spectroscopic
redshifts, within the uncertainty of the photometric method. The redshift
distribution is given for selected ELAIS bands and colour-redshift diagrams are
discussed.
  There is a high proportion of ultraluminous infrared galaxies in the ELAIS
Catalogue ($> 10 %$ of 15 $\mu$m sources), many with Arp220-like colours. 10
hyperluminous infrared galaxies and 10 EROs are found in the survey. The large
numbers of ultraluminous galaxies imply very strong evolution in the
star-formation rate between z = 0 and 1.
