Somali expansion lacked a single central direction. [fact]
Finally, in considering the character of the Somali expansion, it should be remembered that this was not a concerted operation under a single direction: it was a disjointed series of clan and lineage movements in which there were many cross-currents of migration as group jostled group in the search for new pastures.
I.M. Lewis, I. M. Lewis, A Modern History of the Som…, loc. 115