I will discuss the role of radio-loud active galactic nuclei (AGN) in continually re-heating the cooling gas in the haloes surrounding elliptical galaxies, and therefore in controlling galaxy growth. I will show that in the local Universe the prevalence of radio-loud AGN activity amongst elliptical galaxies scales strongly with the mass of the central black hole (as Mbh1.6). By estimating the mechanical energy output of these radio sources, I will show that the time-averaged energy output associated with recurrent radio source activity balances the radiative energy losses from the hot gas surrounding the galaxy, for elliptical galaxies of all masses. The recurrent radio-loud AGN activity may therefore provide a self-regulating feedback mechanism capable of controlling the rate of growth of galaxies. I will then discuss our first attempts to extend this work to higher redshifts, and conclude by discussing what will be possible in this field using the new LOFAR telescope.