  The properties of high redshift quasar host galaxies are studied, in order to
investigate the connection between galaxy evolution, nuclear activity, and the
formation of supermassive black holes. We combine new near-infrared
observations of three high redshift quasars (2 < z < 3), obtained at the ESO
Very Large Telescope equipped with adaptive optics, with selected data from the
literature. For the three new objects we were able to detect and characterize
the properties of the host galaxy, found to be consistent with those of massive
elliptical galaxies of M(R) ~ -24.7 for the one radio loud quasar, and M(R) ~
-23.8 for the two radio quiet quasars. When combined with existing data at
lower redshift, these new observations depict a scenario where the host
galaxies of radio loud quasars are seen to follow the expected trend of
luminous (~5L*) elliptical galaxies undergoing passive evolution. This trend is
remarkably similar to that followed by radio galaxies at z > 1.5. Radio quiet
quasars hosts also follow a similar trend but at a lower average luminosity
(~0.5 mag dimmer). The data indicate that quasar host galaxies are already
fully formed at epochs as early as ~2 Gyr after the Big Bang and then passively
fade in luminosity to the present epoch.
