Rotating black holes which saturate a Bogomol'nyi bound

We construct and study the electrically charged, rotating black hole solution in heterotic string theory compactified on a (10 - D)-dimensional torus. This black hole is characterized by its mass, angular momentum, and a (36 - 2D)-dimensional electric charge vector. One of the features of this solution is that for D > 5 its extremal limit saturates the Bogomol'nyi bound. This is in contrast with the D = 4 case where the rotating black hole solution develops a naked singularity before the Bogomol'nyi bound is reached. The extremal black holes call be superposed, and by taking a periodic array in D > 5, one obtains effectively four-dimensional solutions without naked singularities.