  Large-scale cosmic microwave background anisotropies in homogeneous, globally
anisotropic cosmologies are investigated. We perform a statistical analysis in
which the four-year data from the Cosmic Background Explorer satellite is
searched for the specific anisotropy patterns predicted by these models and
thereby set definitive upper limits on the amount of shear, $(\sigma/H)_0$ and
vorticity, $(\omega/H)_0$, which are orders of magnitude stronger than previous
constraints. We comment on how these results might impact our understanding of
primordial global anisotropy.
