 The chapter on the Byzantine Empire - known in the Muslim world as, and called by the Byzantines themselves, the "Lands of the Romans" - gives his first-hand observation of the 360 languages spoken in the Caucasus, with the Lingua Franca being Arabic and Persian across the region.With the description of Kiev, he may have mentioned the route of the Volga Bulgars and the Khazars, which was perhaps taken from Sviatoslav I of Kiev.He also published a cartographic map of Sindh together with accounts of the geography and culture of Sindh and the Indus River.