This research project aims to join efforts and consolidate the cooperation of a group of researchers with deep-rooted expertises and skills in different areas close or directly related to the AGN phenomenon, and with important national and international collaborations. We plan to make significant contributions to the resolution of some of the most important challenges in the research frontiers of AGNs covering a large range of intrinsic luminosities (from LINERs to QSOs), accretion rates (low and high), scales (from the central SMBHs to galaxy clusters), and redshifts (from the local volume to high-z objects), and for the first time integrating also the perspective allowed by numerical simulations. At the smallest scales, we plan to study the physical properties of the AGN central engines specially in radio loud quasars, to determine the properties of the obscuring torus in LINERs and Seyferts, to test the Unified Model in Seyferts and to analyze the eventualdisappearance of the BLR at the lowest AGN luminosities and/or accretion rates. At scales of the host galaxy, we plan to derive thekinematic and stellar content properties of Seyferts and LINERs and relate them to the AGN fuelling mechanisms, as well as to study the fueling and feedback of star formation and nuclear activity in nearby objects. At the largest scales, from close pairs to galaxy groups with tens of members, we plan to analyze the environments of radio galaxies and type 1 AGN. More specifically, the aim of the subproject "Feeding, feedback and obscuration in active galaxies" is to study 1) how AGN are triggered in Seyfert galaxies and quasars; 2) the impact that nuclear activity has in the host galaxies; and 3) the obscuring structures that hide the AGN central engines. Considering the key role that nuclear activity plays in galaxy evolution, it is necessary to unveil the AGN internal structures and investigate how they are triggered and how they quench, or otherwise relate to star formation in the host galaxies. Linking these aspects of AGN research will provide a better understanding of the physics of galaxies in general.