Final answer:
Cyrus II stabilized the Persian Empire by allowing conquered peoples to maintain their own customs, which in turn fostered loyalty and minimized resistance. He organized the empire into satrapies, led by satraps who balanced local autonomy with imperial oversight. This coupled with modest taxation and strategic military practices contributed to the empire's stability.
Step-by-step explanation:
The Persian king Cyrus II kept his empire stable primarily by letting people in captured lands keep their own customs. This approach was unlike the Assyrians and Neo-Babylonians who previously employed harsher methods of rule. Cyrus II and his successors recognized the importance of maintaining an image of benevolence. They allowed subjects to practice their own religions, speak their own languages, and uphold their own local traditions. This leniency fostered loyalty, minimized uprisings, and the efficient administration facilitated by a system of governors known as satraps, and the 'eyes and ears of the king' helped maintain control over the vast Persian Empire.
Additionally, the empire was organized into satrapies, with a governance structure that included both a political governor and a military general. This system of checks and balances, alongside moderate taxation and a standing army only during wartime, contributed to the stability and longevity of the Persian Empire. The legacy of these policies influenced subsequent conquerors, notably Alexander the Great, who respected and adopted these principles during his own reign over the Persian territories. The inclusion of diverse troops in the military from different regions, each contributing their own strengths, further emphasized the importance of regional autonomy within the wider imperial framework.