Why did King Xerxes castrate the eunuchs?

King Xerxes of Persia castrated eunuchs primarily to ensure their loyalty and eliminate any potential threat to his power. By removing their ability to father children, he made them less likely to establish rival factions or dynasties. Eunuchs often held significant positions in the royal court, and their castration reinforced their dependence on the king for their status and livelihoods. This practice was common in various ancient cultures to control and utilize individuals in specific roles without the risk of familial ambitions.