The HST has made many contributions to all areas of research in the field of AGN, and I have selected three topics where major progress in our understanding has been made over the last two years. The study of the NLR is key to understanding to what extent the unified model for AGN is applicable. In particular, understanding how the NLR is ionized and how its morphology is defined makes an important contribution to clarify the differences between Seyfert 1 and Seyfert 2. Work by Macchetto et al., Capetti et al., Axon et al., and Wilson et al. has helped clarify the picture. Our work on NGC 1068, Mrk 3, Mrk 7, Mrk 348, Mrk 6, and Mrk 573 has shown the following important properties: a) all AGN with a linear radio jet show emission-line morphology ([O III], [O II], Hα) which is aligned along the jet in a surrounding cocoon; b) those AGN with radio lobes show emission-line morphology which is filamentary and coincident with the position of the lobes; and c) in NGC 1068 and in Mrk 3 we have measured transverse velocities to the radio-jet as large as 1700 km s−1. These velocities measured at different positions across the radio-jet show an almost perfect velocity ellipsoid, indicating that the cocoon around the jet is expanding, compresses the ISM and shocks and ionizes the region.