I will present recent findings on the evolution of the properties of the progenitors of local ultra-massive galaxies over the past 11.2 billion years (i.e., since redshift z=3), along with recent results on their environment out to z=2 and of the relative role played by merging and in-situ star formation in the growth of their stellar mass content in the last 10 billion years. I will present the most recent and comprehensive census of quiescent, unobscured and dusty star-forming galaxies as a function of stellar mass since z=3. I will then show very exciting results from a spectroscopic follow-up programs of candidates of very massive galaxies at 1.54). I will conclude by giving a preview of latest on-going observational efforts (e.g., HFF-DeepSpace, NMBS-II, and others)