Muon and pion decays, an electroweak case for EHF

The experimental status of rare muon decays is reviewed. Since the probably last round of those experiments at the present meson factories is being proposed now, any further progress is only possible with a new machine with higher muon flux, for which EHF is a good candidate. In the written version of the talk, reference is made to recent review articles published elsewhere. As an example for a second generation experiment done with an instrument specifically designed for a rare muon decay experiment (SINDRUM) the first observation of the decay π→3eν is reported. (orig.)