Abstract 

  We have mapped the extended submillimeter environments around 14 High-z Radio Galaxies (HzRGs) at redshifts 4.5, 3.5, 2.5 and 1.5 using SCUBA-2 on the James Clerk Maxwell Telescope. This constitutes one of the largest uniform submillimeter surves of HzRG environments to date. In most cases we detect clear overdensities of submillimeter galaxies (SMGs) around the radio galaxies, confirming these to be highly mass biased regions in the universe. We have delineated the average strength of these SMG-overdensities as a function of redshift and find tentative evidence of evolution. The radial profile of the SMG-overdensity as measured from the radio galaxy and outwards exhibit systematic features which may also depend on redshift and radio luminosity of the central radio galaxy.