The following period, embracing nearly 150 years, was a time of decay and degeneracy. With Xerxes began the corruption of the Persian court--the licentiousness, assassinations, murders, and accompanying crimes which soon undermined the entire social order. Conditions were such that rulers were no longer strong, vigorous men, full of life and ambition--save indeed those usurpers who occasionally appropriated the reins of government. The days of Persian greatness were over, and under guidance of one or another of the princes, the state plunged on to ruin. In 336 B.C., Alexander, the young king of Macedonia, embarked upon his world conquests, and the Persian Empire merged into the Empire of Greece. [Illustration: THE PERSIAN KING (WITH ATTENDANTS).] FOOTNOTES: [1] Ragozin: Persia. CHAPTER XX. MANNERS AND CUSTOMS AMONG THE PERSIANS. There were wide differences between the civilization of the Persians and of the dwellers in the Tigris-Euphrates valleys. The Persian despised trade. His religion taught him to speak the truth, and he regarded commercial dealings as incompatible with this requirement. No shops made the principal streets in his country the scenes of hot disputes concerning prices and wares. The few shops which existed at all were tucked into obscure places on unfrequented by-ways. It naturally followed that there was an absence of those industrial centers which in Babylonia produced rare stuffs, delicate fabrics and ornaments. Swarms of slaves provided whatever was required by the wealthy, and it was the Persian's boast that his sword brought him the luxury of the world in tribute. It has been estimated that the total population of Persia did not exceed 2,000,000. A small proportion of these were peasants who tilled the arable soil. Agriculture was held honorable and was encouraged by the national religion. The great majority of men were soldiers.