What term describes a person who owes allegiance to a more powerful individual and receives protection?

The term that describes a person who owes allegiance to a more powerful individual and receives protection is "Client." In the context of ancient Rome, a client was someone who relied on a patron—a wealthier and more influential person—for support and protection. This relationship was mutually beneficial. The client would offer loyalty and services to the patron in exchange for various advantages, such as legal protection, social support, or economic assistance. This patron-client relationship was a fundamental part of the social structure in Roman society.

The other terms may overlap in meaning but refer to different nuances within hierarchical relationships. For instance, "Patron" refers to the more powerful individual providing protection and resources, while "Vassal" is a term mainly used in a feudal context, emphasizing landholding and loyalty in a monarchic system. "Allegiant," while denoting loyalty, does not specifically capture the exchange of protection for allegiance seen in the client-patron dynamic. Thus, "Client" is the most accurate term for this particular relationship.