The submillimetre extragalactic background light is comparable with or exceeds that of the optical and ultraviolet (UV) wavelength ranges, showing directly that much of the energy radiated by star formation and active galactic nuclei is moved to farinfrared wavelengths. However, it is only as this background at 850 m has been resolved with direct submillimetre imaging that we have seen that it is largely created by a population of ultraluminous (or near–ultraluminous) infrared galaxies, which appear to lie at relatively high redshifts (z > 1). Mapping the redshift evolution of this major portion of universal star formation has been difficult because of the poor submillimetre spatial resolution, but this difficulty can be overcome by using extremely deep centimetre continuum radio observations to obtain precise astrometric information, since the bulk of the brighter submillimetre sources have detectable radio counterparts. With this precise position information available, we find that most of the submillimetre sources are extremely faint in the optical and near–infrared (I ≫ 24 and K = 21–22) and inaccessible to optical spectroscopy. Rough photometric redshift estimates can be made from combined radio and submillimetre energy distributions. We shall refer to this procedure as millimetric redshift estimation to distinguish it from photometric estimators in the optical and near–infrared. These estimators place the bulk of the submillimetre population at z = 1–3, where it corresponds to the high–redshift tail of the faint centimetre radio population. While still preliminary, the results suggest that the submillimetre population appears to dominate the star formation in this redshift range by almost an order of magnitude over the mostly distinct populations selected in the optical/UV.