Owing to large surveys with the Hubble Space Telescope and ground-based telescopes we now have high resolution snapshots of the Universe dating back to only a few hundred million years after the Big Bang. The challenge now is to use this wealth of data to figure out how galaxies assembled, and what physical processes drove their evolution. The talk will highlight recent results on the evolution of the most massive galaxies, as these galaxies are in some ways the easiest to study out to high redshifts. We now have a self-consistent description of the evolution of these galaxies from compact, star forming ancestors at z~3 to their giant passively evolving descendants today. Interestingly, we do not yet understand why these galaxies followed this particular path; spectroscopic surveys such as the 3D-HST project may shed light on the physics behind the observed events.