Abstract: Hierarchical power estimation and throttling in a processor-based system in an integrated circuit (IC) chip, and related power management and power throttling methods are disclosed. The IC chip includes a processor as well integrated supporting processing devices for the processor. The hierarchical power management system controls power consumption of devices in the IC chip to achieve the desired performance in the processor-based system based on activity power events generated from local activity monitoring of devices in the IC chip. The hierarchical power management system includes a centralized power estimation and limiting (PEL) circuit that is configured to track and merge received power throttle recommendations associated with related activity power events for monitored processing devices to generate one or more power limiting management responses to throttle power consumption of related devices that may be contributing to excess power consumption.