  We study a deSitter/Anti-deSitter/Poincare Yang-Mills theory of gravity in
d-space-time dimensions in an attempt to retain the best features of both
general relativity and Yang-Mills theory: quadratic curvature, dimensionless
coupling and background independence. We derive the equations of motion for Lie
algebra valued scalars and show that in the geometric optics limit they
traverse geodesics with respect to the Lorentzian geometry determined by the
frame fields. Mixing between components appears to next to leading order in the
WKB approximation. We then restrict to two space-time dimensions for
simplicity, in which case the theory reduces to the well known
Katanaev-Volovich model. We complete the Hamiltonian analysis of the vacuum
theory and use it to prove a generalized Birkhoff theorem. There are two
classes of solutions: with torsion and without torsion. The former are
parametrized by two constants of motion, have event horizons for certain ranges
of the parameters and a curvature singularity. The latter yield a unique
solution, up to diffeomorphisms, that describes a space constant curvature .
