  Magnetic confinement of the winds of hot, massive stars has far-reaching
consequences on timescales ranging from hours to Myr. Understanding the
long-term effects of this interplay has already led to the identification of
two new evolutionary pathways to form `heavy' stellar mass black holes and
pair-instability supernova even at galactic metallicity. We are performing 1D
stellar evolution model calculations that, for the first time, account for the
surface effects and the time evolution of fossil magnetic fields. These models
will be thoroughly confronted with observations and will potentially lead to a
significant revision of the derived parameters of observed magnetic massive
stars.
