Galactic archaeology with metal poor stars from the Pristine survey The Milky Way is a spiral galaxy consisting of a disc of gas dust and stars embedded in a halo of dark matter. Within this dark matter halo there is also a diffuse population of stars called the stellar halo that has been accreting stars for billions of years from smaller galaxies that get pulled in and disrupted by the large gravitational potential of the Milky Way. As they are disrupted these galaxies leave behind long streams of stars that can take billions of years to mix with the rest of the stars in the halo. Furthermore the amount of heavy elements (metallicity) of the stars in these galaxies reflects the rate of chemical enrichment that occurred in them since the Universe has been slowly enriched in heavy elements (e.g. iron) through successive generations of stars which produce them in their cores and supernovae explosions. Therefore stars that contain small amounts of heavy elements (metal poor stars) either formed at early times before the Universe was significantly enriched or in isolated environments. The aim of ...