👉 In the context of diplomacy and international relations, a "vassal" refers to someone who is loyal or obedient to another party. This can include military vassals in feudal systems, or diplomats and officials in diplomatic relationships. In modern terms, vassalage typically refers to the role of an individual as a vassal of another person, such as a spouse or parent. In historical contexts, vassalage was often used to justify the power of a ruler over their subjects