  We describe an ab initio theory of finite temperature magnetism in
strongly-correlated electron systems. The formalism is based on spin density
functional theory, with a self-interaction corrected local spin density
approximation (SIC-LSDA). The self-interaction correction is implemented
locally, within the KKR multiple-scattering method. Thermally induced magnetic
fluctuations are treated using a mean-field `disordered local moment' (DLM)
approach and at no stage is there a fitting to an effective Heisenberg model.
We apply the theory to the 3d transition metal oxides, where our calculations
reproduce the experimental ordering tendencies, as well as the qualitative
trend in ordering temperatures. We find a large insulating gap in the
paramagnetic state which hardly changes with the onset of magnetic order.
