How did our Galaxy form? What is its place, and ours, in the cosmic evolution? This ARCHEOGAL ANR project aims at unveiling the Milky Way disc formation process, taking advantage of the privileged position of the P.I in the European Gaia-ESO Survey (GES, a five years project using 300 nights of the ESO Very Large Telescope) and the ESA Gaia mission, whose time-lines overlap perfectly the present project time schedule. Just as the history of life was deduced by examining rocks, Galactic Archaeology expects to unveil the history of the Milky Way by analysing stars. Thanks to the complementary scientific exploitation of GES and Gaia, ARCHEOGAL aims at building up an unprecedentedly extensive and homogeneous cosmic-time evolving chemo-dynamical picture of the Milky Way disc. To this purpose, the project tasks, organised following the GES and Gaia data releases, will analyse the disc physical and chemical properties, linking them to the processes that led the Milky Way to form and evolve as a disc-type galaxy, in the more general context of galaxy evolution. In particular, the project work program is centred on: 1) The GES stellar spectra parameterisation and the scientific validation of the Gaia/RVS stellar parameters. 2) From GES and Gaia chemical element abundances, the analysis of the Galactic disc chemical substructures. 3) From GES spectro-photometric distances, followed by Gaia astrometric data, the study of the structural properties of chemically defined disc populations. 4) Thanks to GES+Gaia radial velocities and Gaia proper motions, the analysis of existent chemo-kinematical and chemo-dynamical correlations. 5) From combined Gaia+GES data, the estimation of precise stellar ages and the reconstruction of chemo-dynamical temporal gradients, to be compared with present scenarios of disc formation. This ANR funding will be crucial to ensure the team's leading position in GES and also to strength the French contribution to the combined GES and Gaia science exploitation.