The Inca and what other civilization used a hostage-style system to centralize control in their capital and keep an eye on potential threats?

The Aztecs used a hostage-style system similar to the Inca to centralize control in their capital, Tenochtitlan. The Aztecs would demand tributes from conquered territories, including the rulers' children, who were taken hostage and brought to the Aztec capital. These hostages were treated well but were closely monitored to ensure their loyalty and deter any rebellions or uprisings. This strategy allowed the Aztec ruling elite to exert control over their empire and eliminate potential threats or challenges to their authority.