If the name Parsua could signify Persians, the inscriptions of the kings of Asshur would confirm the division of the Persians into several tribes. Shalmanesar II. tells us, that in the year 833 B.C. he received tribute from the heads of the Parsuas, as the inscription says: from twenty-seven princes of the Parsuas. Afterwards Tiglath Pilesar II. traversed the land of the Parsuas and imposed tribute upon them (744 B.C.).[516] The books of the Hebrews confirm Esarhaddon's dominion over Persia, inasmuch as they tell us that he settled Persians and Dai (Dahas) in Samaria (III. 154). It must have been in the period of the supremacy of Assyria, at the latest in the first half of the seventh century B.C., that the worship of the gods, which the Persians shared from all antiquity with their fellow-tribesmen on the table-land of Iran, the worship of Mithra, Vayu, Anahita, and fire, underwent the change which bears the name of Zarathrustra. As we saw good reason to assume, the new doctrine first came to the Medes from the North-East; from the Medes it passed, without doubt, to the Persians. If Herodotus places the Magians, or special priestly order, among the tribes of the Medes and not among those of the Persians, among whom Strabo is the first to mention them, the conclusion is, as has been sufficiently proved, not that the Persians were without priests before and after the reform, but rather that even after the reform the priestly families remained in their natural unions, and did not form themselves into a special tribe (p. 192). The supremacy of Assyria over the West of Iran came to an end when Phraortes united the tribes of the Medes under his leadership, and, towards the year 640 B.C., undertook to maintain the independence of Media against Assurbanipal, the successor of Esarhaddon. In this struggle the Persians joined the Medes and ranged themselves under them. Herodotus, who obviously follows the tradition of the Medes, represents Phraortes as marching against the Persians, conquering and subjugating them; according to the Persian account, which is preserved in Ctesias, the chief of the Medes induced the Persians to revolt against the Assyrians, and to join him, by the promise that they should remain free under his leadership (III. 250). The situation of affairs agrees better with the second version than with the first. Considering the enormous power which Assyria under Assurbanipal possessed down to the middle of the seventh century, it is hardly probable that Phraortes would have inaugurated the recent independence of Media by an attack on the Persians, which might, and indeed must, drive them into the arms of the Assyrians. It is far more probable that the two nations formed a league against Assyria. As already observed, the annihilation of the kingdom of Elam, which Assurbanipal accomplished in the year 645 B.C., would supply the Persians with a strong incentive to unite themselves with the kindred and more powerful nation of the Medes.