The primordial universe : Les Houches LXXI This book reviews the interconnection of cosmology and particle physics over the last decade. It provides introductory courses in supersymmetry superstring and M theory responding to an increasing interest to evaluate the cosmological consequences of these theories. Based on a series of extended courses providing an introduction to the physics of the very early universe in the light of the most recent advances in our understanding of the fundamental interactions it reviews all the classical issues (inflation primordial fluctuations dark matter baryogenesis) but also introduces the most recent ideas about what happened at the Big Bang and before. The Universe at High Redshift Cosmological Parameters and Galaxy Formation A Short Course on Big Bang Nucleosynthesis The Cosmic Microwave Background: From Detector Signals to Constraints on the Early Universe Physics to Supersymmetry: Astrophysical and Phenomenological Constraints Dark Matter: Direct Detection Inflation and Creation of Matter in the Universe Cosmological Constant vs. Quintessence Gravitino Production and Super Higgs Effect in Cosmology Physics of the Early Universe: Baryogenesis; Defects; Initial Conditions M Theory and Cosmology String Cosmology: The pre Big Bang Scenario.