Who were the military commanders in the Vijayanagara Empire who controlled forts and had armed supporters?

Nayakas

Among those who wielded influence within the empire were military commanders who typically oversaw fortifications and maintained armed support. These commanders frequently migrated from one region to another, often accompanied by peasants seeking arable land for settlement. These commanders, commonly referred to as "nayakas," predominantly spoke Telugu or Kannada. While many nayakas acknowledged the authority of the Vijayanagara kings, they frequently rebelled, necessitating military interventions to quell their uprisings.

The amara-nayaka system represented a significant political innovation within the Vijayanagara Empire, likely drawing inspiration from the iqta system of the Delhi Sultanate.