Flavius Philostratus' "Life of Apollonius of Tyana" (v.2) says, "And they also say that the Islands of the Blessed are to be fixed by the limits of Libya where they rise towards the uninhabited promontory." In this geography Libya was considered to extend westwards through Mauretania "as far as the mouth of the river Salex, some nine hundred stadia, and beyond that point a further distance which no one can compute, because when you have passed this river Libya is a desert which no longer supports a population".