The idea for the Hubble Deep Fields originated in results from the first deep images taken after the repair in 1993. These images showed many galaxies, which were often quite unlike those we see in the local Universe and could not otherwise be studied using conventional ground-based telescopes. The first Deep Field, the Hubble Deep Field North (HDF-N), was observed over 10 consecutive days during Christmas 1995. The resulting image consisted of 342 separate exposures, with a total exposure time of more than 100 hours, compared with typical Hubble exposures of a few hours. The observed region of sky in Ursa Major was carefully selected to be as empty as possible so that Hubble would look far beyond the stars of our own Milky Way and out past nearby galaxies.