  Radio-loud AGN play an important r\^ole in galaxy evolution. We need to
understand their properties, and the processes that affect their behaviour in
order to model galaxy formation and development. We here present preliminary
results of an investigation into the cluster environments of radio galaxies. We
have found evidence of a strong correlation between radio luminosity and
environment richness for low excitation radio galaxies, and no evidence of
evolution of the environment with redshift. Conversely, for high excitation
radio galaxies, we found no correlation with environment richness, and
tentative evidence of evolution of the cluster environment.

Astrophysics of Galaxies;Cosmology and Nongalactic Astrophysics