Institution(s): 1. University of Geneva
We shall begin by reviewing some observed properties of red supergiants and see to which extent these properties can be reproduced by stellar models. We shall discuss the physics that makes some massive stars to become red supergiants, as well as the physics which may make them evolve back to the blue. One of the key processes is mass loss which may arise from stellar winds and/or from mass transfers in close binaries. We shall discuss some observational features that can be used to constrain the post red supergiant evolution as well as the consequences for the frequency of various types of core collapse supernovae.