  Collapsed ancient solutions to the homogeneous Ricci flow on compact
manifolds occur only on the total space of principal torus bundles. Under an
algebraic assumption that guarantees flowing through diagonal metrics and a
tameness assumption on the collapsing directions, we prove that such solutions
have additional symmetries, i.e., they are invariant under the right action of
their collapsing torus. As a byproduct of these additional torus symmetries, we
prove that these solutions converge, backward in time, in the Gromov-Hausdorff
topology to an Einstein metric on the base of a torus bundle.
