Accretion onto a supermassive black hole (BH) is the most viable explanation for the huge emitted luminosity in active galaxies. Nowadays a wealth of observations have shown the presence of a BH in many nearby inactive bulges, suggesting that all massive spheroids harbor a BH. Moreover, at low redshift, fundamental correlations have been found between the BH mass and the luminosity (mass) and the central velocity dispersion of the host galaxy bulge. These correlations underline the important fact that there must be a strong relationship between the formation and evolution of massive bulges and their central BH. We discuss our ongoing program to investigate the cosmic evolution of this relationship. Optical (rest-frame UV) spectroscopy is used to determine the virial BH masses of a large sample of high redshift quasars for which the host galaxy luminosity is reliably determined from our previous VLT imaging.