The farmers, peasants and operatives of Media and Persia--so admired even by Xenophon and Plato--thus built up a vigorous state and society. After long centuries of existence, however, its strength was undermined by foreign conquests, by luxury, and by political and domestic slavery. A similar phenomenon will present itself again and again in the course of this investigation. When the Medes overthrew the Assyrian empire, they became infected with the dissolute customs of their former masters. The houses of the wealthier were filled with domestic slaves; though, as yet, slavery did not come in contact with agriculture or the industrial pursuits, and so spread like a blight over the land. Domestic slavery, in the limited sense of household servitude, was doubtless ultimately introduced into Persia; but never was Persian held as _chattel_ on his ancestral soil. Nor yet did despotism, or political slavery, exist in the governmental structure of the Iranians, who, led by Kyros (Cyrus), conquered the whole western Asiatic world. Kyros was only the first among his peers, and was all-powerful only as a leader and commander. He had not yet the despotic power of Xerxes and other and later scions of the Achæmenides; and to the last, even to the conquests by Alexander, the Iranic social structure was comparatively free from domestic slavery. Nor were the Persians and other Iranian tribes ever the absolute political slaves of their own kings. The Persian conquerors of the Asiatic world found domestic slavery more or less developed wherever they penetrated. Positive information, however, is extremely scanty regarding the special social and political organization of the Persians after Kyros and under Dareios. The rule of the Achæmenides extended over about eighty millions of men, belonging to various races. The conquerors, in all cases, respected the civil and social organization and administration peculiar to the subjugated tribes or nations. In numerous instances, the sovereigns of conquered states became Persian satraps over lands they once ruled in their own right. As satraps they were possessed of oppressive authority, had the power of life and death, of forcing exactions and levying taxes. But, as the Persian kings were, to the last, strict observers of Zarathustra's precepts, agriculture always continued to be the most favored pursuit. The satraps were rewarded with strict reference to the degree in which agriculture flourished and the population grew and prospered in their respective satrapies. During the long rule of the descendants of Dareios, comparative peace prevailed in the interior of the great empire, which swept from the Nile almost to the Indus. So that domestic slavery did not find its usual supplies from prisoners of war, or by the destruction of small properties and consequent domestic impoverishment--those terrible sequels of wars from which Fore-Asia had suffered almost uninterruptedly for many previous centuries.