2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/7086Some recent results on the physical and statistical properties of nearby and distant AGN are presented. I first discuss the properties of "elusive" AGNs, i.e. obscured AGNs which do not show a Seyfert-like spectrum in the optical. Then I present preliminary results from a detailed study of the contribution of obscured AGNs and of their host galaxies to the infrared cosmic background. Finally I discuss an observational program aimed at investigating the properties of the most distant quasars, of their circumnuclear medium and the implications for their host galaxies.6 pages. Invited talk to appear in "Multiwavelength Mapping of Galaxy Evolution" eds.R.Bender and A.RenziniAstrophysicstext