  We construct the general electrically charged, rotating black hole solution
in the heterotic string theory compactified on a six dimensional torus and
study its classical properties. This black hole is characterized by its mass,
angular momentum, and a 28 dimensional electric charge vector. We recover the
axion-dilaton black holes and Kaluza-Klein black holes for special values of
the charge vector. For a generic black hole of this kind, the 28 dimensional
magnetic dipole moment vector is not proportional to the electric charge
vector, and we need two different gyromagnetic ratios for specifying the
relation between these two vectors. We also give an algorithm for constructing
a 58 parameter rotating dyonic black hole solution in this theory,
characterized by its mass, angular momentum, a 28 dimensional electric charge
vector and a 28 dimensional magnetic charge vector. This is the most general
asymptotically flat black hole solution in this theory consistent with the
no-hair theorem.
