Abu Abd Allah al-Jayhani

Abu Abd Allah al-Jayhani was vizier of the amir of Khurasan; al-Muqaddasi names him first among the authors of routes and realms he criticizes in the preface of the Ahsan al-taqasim. ¹

Al-Muqaddasi says al-Jayhani was a man of philosophy, astrology and astronomy who gathered strangers and asked them about the realms and their revenues, the roads to them, the height of the planets there and the length of shadows, in order to learn how to conquer countries and know their income and to perfect his astrology and his knowledge of the heavens' rotation. ^{1 2} He faults him for dividing the world into seven climes with a planet for each, for writing of stars, geometry and things of no use to ordinary people, for describing the idols of India and the marvels of Sind and detailing land tax, and for listing unknown halting places and abandoned stages while neither detailing the districts, ordering the provinces nor describing the cities, giving instead the roads east, west, north and south with their plains, mountains, valleys and rivers, which made his book long. ² All this is al-Muqaddasi's assessment.