What role payment of tribute play in the government of the parthian empire?

In the Parthian Empire, the payment of tribute served as a crucial mechanism for maintaining control over vassal states and ensuring loyalty among conquered territories. It provided a steady stream of revenue for the Parthian rulers, which was essential for funding military campaigns and administrative functions. Additionally, tribute payments reinforced the hierarchical structure of the empire, where local leaders were incentivized to support the central authority in exchange for protection and favor. This system helped the Parthians manage a vast and diverse empire effectively.