M31 and companions: A key to Baade's stellar populations then and now

The stellar populations in M31 and its companions are reviewed from both hi storical and more modern contexts. Recent data for nearby resolved galaxies suggest that a revision of Baade's original population concept, particular ly as applied to elliptical galaxies, is required. In addition, these new d ata highlight the difficulties in interpreting the data for, and the lack o f direct information on, the more distant giant elliptical galaxies being u sed for cosmological studies.