Based on the first 4 years of Fermi operation, the third catalogue of
active galactic nuclei detected by the Large Area Telescope on board the
Fermi satellite included approximately 1600 gamma-ray sources located at
high Galactic latitudes, and statistically associated with AGN. The large
majority of these AGN are blazars, but also different types of gamma-ray
emitting AGN such as radio galaxies and narrow-line Seyfert 1 galaxies are
detected.
When combined with contemporaneous ground- and space-based observations,
Fermi-LAT achieves its full capability to characterize the jet structure
and the emission mechanisms at work in radio-loud AGN. In this talk I will
discuss the radio-to-gamma-rays properties of blazars, radio galaxies, and
narrow-line Seyfert 1 galaxies, highlighting major findings and open
questions regarding the physics of AGN in the Fermi era.