Galaxies like the Milky Way are surrounded by large amounts of diffuse gas that connect the stellar body of a galaxy with the surrounding cosmological large-scale structure. This diffuse gas component, commonly referred to as circumgalactic medium (CGM), plays a key role in the on-going formation and evolution of galaxies in the local Universe. In this talk I will review our current understanding of the distribution and physical nature of the circumgalactic gas surrounding the Milky Way and discuss recent observational and theoretical studies of the local CGM that provide important new information on the past and future evolution of our Galaxy. In particular, I will present new results on the origin of the so-called Magellanic Stream based on data obtained with the Hubble Space Telescope and the ESO Very Large Telescope