Depends upon what we call as historical. Strictly speaking it is extremely difficult to be hundred percent certain about anything of remote history in terms of actual excavations and remains of the era. So one has to rely on written documents and oral transmission (since written records came later). Much of history is by way of such accounts. In this sense it is very much historical as it is documented in the Seventh Mandala of the Rig Veda.
Affectionately,
Alok Da


