These are my lectures held at the Beijing International Summer School тАЬThe Physics and Evolution of AGNsтАЭ which was held in Beijing on September 3-9, 2011.

Part 1: Supermassive black holes in galactic nuclei: detections and mass measurements

Part 2: Scaling relations between black holes and their host galaxies

Part 3: The cosmological evolution of AGN and BHs

Part 4: The observational signatures of coevolution