  We present a microscopic theory of the anomalous Hall effect in metallic
multi-band ferromagnets, which accounts for all scattering-independent
contributions, i.e., both the intrinsic and the so-called side jump. For a
model of Gaussian disorder, the anomalous Hall effect is expressed solely in
terms of the electronic band structure of the host material. Our theory handles
systematically the interband-scattering coherence effects. We demonstrate the
method in the two-dimensional Rashba and three-dimensional ferromagnetic
(III,Mn)V semiconductor models. Our formalism is directly amenable to ab initio
treatments for a wide range of ferromagnetic metals.
