Final answer:
The nobles primarily served under royal employment in ancient civilizations.
Step-by-step explanation:
The group that primarily served under royal employment in ancient civilizations was the nobles.
During the ancient times, the ruling order, which included priests, warriors, and nobles, held positions of power and influence. They were often appointed by the king or queen to serve in administrative roles, lead armies, or oversee religious affairs.
For example, in Neo-Assyrian society, the ruling order consisted of nobles, while other social classes like peasants, merchants, and artisans served different roles within the society.