The Universe started its expansion 13.8 Gyr ago. After some 10⁸ years the gas in the Universe was ready to form stars. Just this epoch must be inspected to search for galaxy population dawn — the first gravitationnaly bound stellar systems may form just then. The present-day astronomical observation tools — ground-based interferometers and space telescopes — allow study directly the properties of galaxies at their earliest evolutionary stages, in the first Gyr of the Universe expansion: their structures, sizes, masses, star formatrion rates and nuclear activity. This brief review presents the latest results of such studies.