Probably, more significantly, their warriors were sometimes mounted on horseback, a technique which the Oromo later adopted and used to good effect in their massive migration into Abyssinia. Yet it was probably above all their overwhelming numerical superiority, and the dynamism which their movement acquired, which enabled the Somali to conquer so much territory at the expense of the Oromo.

I.M. Lewis, I. M. Lewis, A Modern History of the Som…, loc. 115