The young expanding Universe,at its first moments,went through a series of transitions which shaped its present structure.Our understanding of these phases comes from direct observation of the Cosmos,using various messengers from the past.It also comes from experiments performed at colliders,allowing to re-create at small scale the physics which prevailed at a given time in the evolution of the Universe.Facts are reasonably well established until the first picosecond (10**-12 s).At shorter times one needs to extrapolate within various models,and hypotheses replace certainties,in particular concerning the short win of matter over antimatter.The present status of our understanding will be reviewed.Special attention will be given to results from the LHC collider including the recently announced discovery of a new particle,as well as to recent advances in neutrino physics.