Proto-Daju has been partially reconstructed by Robin Thelwall (1981). In his judgement, the Eastern Daju languages separated from the others perhaps as much as 2,000 years ago, while the Western Daju languages were spread more recently, perhaps by the Daju state which dominated Darfur from about 1200 AD until scattered after the death of Kasi Furogé, the Daju king, and replaced by the Tunjur. The principal phonetic difference between the two branches is the reflex of proto-Daju *ɣ, reflected as Western *r and Eastern *x.