  A sample of FRII radio sources in rich clusters of galaxies, both at high
(z$\sim$0.5) and low (z$\sim$0) redshift, has been constructed to study the
effect of environment on radio sources. Comparisons are made between the
properties of FRII sources in cluster and non-cluster environments, and between
X-ray clusters with and without FRII sources. The principal results are the
following:
  1. Most low-redshift FRII sources in clusters appear to be similar to FRII
sources in group or field environments in terms of radio power, optical
properties of the host galaxy, and nonthermal pressure of the radio bridge.
Most low-redshift clusters with FRII sources tend to lie at the lower end of
cluster X-ray luminosity distribution, some having $L_x$ comparable to FRII
sources in non-cluster environments.
  2. High-redshift FRII sources are all quite similar to each other
irrespective of their environments. The nonthermal pressures of their radio
bridges appear to be similar to those of low-redshift FRII's.
  3. The nonthermal pressures of the bridges of FRII sources appear to be
similar to the thermal pressures of the ICM around them. This result would
allow FRII sources to be used as probes of their gaseous environments. The
current data imply that the evolution in the clustering strength around FRII
sources toward high-redshift is likely to be closely linked to an evolution of
the state of the intracluster medium.
