The primary goal of this project is to develop a new type of statistical approach to constrain the assembly of the evolving population of galaxies over cosmic time using modern multi-waveband photometric surveys. This work combines uniquely the expertise of: (1) the proposed fellow, in the development and application of state-of-the-art statistical techniques to interpret galaxy spectral energy distributions (SEDs); (2) the host scientist, in the development of sophisticated models to describe the integrated light emitted by stellar populations; (3) the science team of the TERAPIX data reduction centre of the host institution, which manages archives of two of the biggest multiwavelength photometric surveys to date - the Cosmic Evolution Survey (COSMOS) and the Canada-France-Hawaii-Telescope Legacy Survey (CFHTLS). The method will employ modern multivariate analysis techniques to create photometric “indices” which describe in a compact way the entire SED of a galaxy, independent of redshift. Replacing traditional colour-colour diagrams with such indices will enable a powerful combination of the methods of SED-fitting and diagnostic diagrams of star formation and chemical enrichment history. We will, for the first time, be able to identify and extract the information encoded in the full SEDs of galaxies for entire galaxy populations. By applying the new method to the world leading photometric dataset, COSMOS, we will gain unprecedented insight into timely cosmological issues such as the assembly history and chemical enrichment history of galaxies as a function of stellar mass, and the link between galaxy mergers, star formation and black hole activity.