The nations and condition of Eastern Iran can be ascertained more clearly from the inscriptions of Darius. According to his inscription at Behistun, his empire in that direction comprised the Parthians, Sarangians, Areians, Chorasmians, Bactrians, Sogdiani, Gandarii, Sattagydæ, Arachoti, and Sacæ; and to these the Idhus, _i.e._ the Indians on the right bank of the upper course of the Indus, are added in the inscriptions of Persepolis and Naksh-i-Rustem.[32] Further information is preserved by Herodotus with respect to the tribute imposed by Darius on these nations. As these statements are undoubtedly derived from Persian tribute lists, they serve to throw a side light on the state of civilisation existing in the east of Iran at the division of the sixth and fifth centuries B.C. The Sarangians, who, as we have seen (p. 7), inhabited the fertile land round Lake Areios (Hamun), together with the Sagartians and some neighbouring nations on the south, paid yearly 600 Babylonian talents into the treasury of the king. The Areians (Haraivas), Parthians, Sogdiani, and Chorasmians, who formed the sixteenth satrapy of the Persian empire, had to pay 300 talents; the Gedrosians and Gandarians together paid 170 talents; the Caspiani (_i.e._ no doubt, the Tapurians and other tribes on the southern shore of the Caspian Sea) and the Sacæ, who traversed the steppes of the Oxus, _i.e._ the fifteenth satrapy, paid 250 talents; and the Bactrians, the twelfth satrapy of the empire, paid 360 talents.[33] These sums, which do not include the whole of the burdens of the provinces, but are only the land taxes which they had to pay,--in addition, tolls were levied and contributions in kind to the court of the king and the satraps, as well as for the maintenance of the army,--show that at the time of Darius agriculture and wealth had proceeded far beyond the earliest stages in the eastern districts of Iran. The Babylonian silver talent amounts to more than 2000 thalers (6000 shillings).[34] If a sum of more than 1,200,000 thalers (£180,000) could be raised every year in land tax from the districts round Lake Hamun, extensive though they were, and 720,000 thalers (£108,000) in a similar manner from the land of the Bactrians, the gardens, fields, and pastures of these regions must have been considerable in breadth, and of great fertility.