Co-evolution of black holes and galaxies

One of the most intriguing discoveries of astrophysics in the last decade was to realize that the mass of galactic black holes is tightly correlated to the large scale properties of their host galaxy bulges. The main physical processes at work in shaping this relation is still not clear. One of the main path followed to provide additional constrains to theory is to determine the evolution of the black hole mass - galaxy relation with redshift. I will review in this talk the status in which we are currently standing. I will then report on recent results that we obtained with HST/NICMOS observations of low luminosity host galaxies of z > 1 AGN. The quality of our data allows us to quantify the contribution of disks to the total stellar-mass of our host galaxies. Our work suggest that the ratio between black-hole mass and bulge stellar-mass was already evolving in the last 9 Gyrs.