The Cosmic History of the Universe

With the advent of new space observatories and new instruments on ground-based telescopes, astronomers are mapping much of the star formation and supermassive black hole accretion that produces the light of the universe. The emerging consensus is that the early universe was dominated by a small number of giant galaxies containing colossal black holes and prodigious bursts of star formation, while the more recent universe is surprisingly active in a more dispersed mode---the creation of stars and the accretion of material into black holes is being carried out in a large number of medium-size and small galaxies. I will present observations at many different wavelengths that show this vast downsizing of cosmic activity.