a sufficiently large body of tribute, passed up the line by lesser chiefs. These lesser chiefs in turn collect from those below them, from communities close to their own center. At the apex of the status, hierarchy sits the paramount. Anthropologists and archaeologists have demonstrated through research that chiefdoms are a relatively unstable form of social organization. They are prone to cycles of collapse and renewal, in which tribal units band together, expand in power, fragment through some form of social stress, and band together again. An example of this kind of social organization were the Germanic Peoples who conquered the western Roman Empire in the 5th century CE. Although commonly referred to as tribes, anthropologists classified their society as chiefdoms. They had a complex social hierarchy consisting of kings, a warrior aristocracy, common freemen, serfs, and slaves. The American Indian tribes sometimes had ruling kings or satraps (governors) in some areas and regions. The Cherokee, for example, had an imperial-family ruling system over a long period of history. The early Spanish explorers in the Americas reported on the Indian kings and kept extensive notes during what is now called the conquest. Some of the native tribes in the Americas had princes, nobles, and various classes and castes. The "Great Sun" was somewhat like the Great Khans of Asia and eastern Europe. Much like an emperor, the Great Sun of North America is the best example of chiefdoms and imperial kings in North American Indian history. The Aztecs of Mexico had a similar culture. Chiefdoms on the Indian subcontinent The Indus Valley Civilisation (3300 BCE - 1700 BCE) was a hegemony of chiefdoms with supreme chiefs in each and a system of subsidiary chiefs. The ranks of the chiefs included ordinary chiefs, elders, priests or cattle-owners and head chiefs. The Arthashastra, a work on politics written some time between the 4th century BC and 2nd century AD by Indian author Chanakya, similarly describes the Rajamandala (or "Raja-mandala,") as circles of friendly and enemy states surrounding the state of a king (raja). Also see Suhas Chatterjee, Mizo Chiefs and the Chiefdom (1995). Native chieftain system in China Tusi (), also known as Headmen or Chieftains, were tribal leaders recognized as imperial officials by the Yuan, Ming, and Qing-era Chinese governments, principally in Yunnan. The arrangement is generally known as the Native Chieftain System (). Alternatives to chiefdoms In prehistoric South-West Asia,