at high redshift. Observational properties of massive low-redshift galaxies as well as cosmological simulations suggest that star formation in high-z galaxies was prematurely truncated before star formation could exhaust the available gas supply. Immense winds driven by the energy released from AGN are now the truncation mechanism which is preferred by most cosmological models of galaxy evolution. Detailed models of how radio jets drive such winds have made impressive progress in the last years. For example, they predict that prior to forming well collimated jets upon breakout from the ISM, the jet will very effectively deposit its momentum and energy during a “flood and channel” phase, as it permeates the ISM along low-density channels, in agreement with observations [@sutherland07; @wagner11; @wagner12].

Powerful radio galaxies (HzRGs) at high redshift (z$\ga$2) are ideal sites to study the late formation stages of massive galaxies in the early Universe. They have high stellar [e.g., @debreuck03; @seymour07; @debreuck10] and dynamical masses [@villar03; @nesvadba07b], and high star formation rates of up to 1000 M$_{\odot}$ yr$^{-1}$ [@archibald01; @reuland04; @drouart14], with implied formation times of few 100 Myr. They host luminous, obscured quasars with bolometric luminosities of few $\times 10^{45-46}$ erg s$^{-1}$ [e.g., @carilli02; @overzier05; @drouart14], and have 