The Parkes selected regions : deep optical and infrared observations of radio galaxies and quasars at high redshifts.

We report the results of an extensive optical and infrared study of the 178 radio sources in the Parkes Selected Regions (S > 100 mJy at 2.7 GHz). CCD observations have resulted in the essential completion ( >~95 per cent) of the optical identification programme, and have provided B and R photometry of the new identifications. In addition, K photometry has been completed for four of the six selected Regions. New spectroscopic observations have increased the redshift content to 46 per cent, including virtually all the quasar candidates. We discuss redshift estimation for the remaining radio galaxies in the light of the B, R and K photometry; it appears unlikely that more than 10 objects out of the total of 178 can lie at z > 2.5. We briefly discuss some implications of the database presented here. The ability of this sample to probe high-redshift space has resulted in some important input on the high-redshift cut-off in the radio luminosity function, as well as providing new information on the optical spectral evolution of radio galaxies.