Elliptical galaxies display a misleading simplicity in their structural properties and population homogeneity. A major controversy yet to be resolved is whether they formed "monolithically" at high redshift or assembled hierarchically from the mergers of smaller disk systems, as predicted in popular models of structure formation. I will review the observational progress made in distinguishing between these pictures and present new results based on the combination of HST imaging and Keck spectroscopy of field and cluster ellipticals.