  A radiative hydrodynamic simulation for a typical, powerful high redshift
radio galaxy is presented. The jet is injected at one third the speed of light
into a 10000 times denser, homogeneous medium. In the beginning of the
simulation, the bow shock consists of a spherical shell that is similar to a
spherical blast wave. This shell cools radiatively down to approximately 10,000
K, providing after 6 Mio yrs a neutral column of 3.8 x 10^21 cm^-2 around the
whole system. The shell starts to fragment and forms condensations. This
absorbing screen will cover a smaller and smaller fraction of the radio source,
and therefore the emission line region, and eventually form stars in typically
10,000 globular clusters of one million solar masses. Approximately 10^9 solar
masses are entrained into the radio cocoon. This gas, cooling and illuminated
from the radio source, could be the emission line gas observed in high
redshifted radio galaxies and radio loud quasars. The neutral column behind the
bow shock can account for the absorption found in almost all of the small
sources. The globular cluster excess of approximately 10^4 systems found in
present day brightest cluster galaxies (BCGs), which are believed to be the
vestiges of these objects, is consistent with the presented scenario.
