Elliptical galaxies are the oldest galactic systems in the local Universe. How and when were they formed? How do these massive galaxies relate to quasars and sub-mm sources? These fundamental issues are still controversial and unresolved, but theories of galaxy formation have now matured to the point where they are beginning to make clear, testable predictions.
The primary aim of this proposal is to determine the comoving number density of passively evolved ellipticals at high redshift. Answering this very basic question will test the fundamental principles of hierarchical structure formation. At the conclusion of the recent New Era in Cosmology conference in Durham (September 2001), the final discussion panel (including Peebles, White, Frenk & Madau) agreed on a definitive observational test of the CDM paradigm. Specifically, it was agreed that if >1/3 of L* ellipticals were in place by z=3, all current CDM-based models would be rendered untenable.