Rouran Khaganate

The Rouran Khaganate (Chinese:柔然; Róurán), also known as Ruanruan or Juan-juan (蠕蠕; Ruǎnruǎn) (or variously Jou-jan, Ruruan, Ju-juan, Ruru, Ruirui, Rouru, Rouruan or Tantan), was a tribal confederation that were before the Chinese extermination campaign of 93 a.C. Xiongnu and that then moves East, while the current Mongol population moved to Mongolia, the Proto-Mongolic Donghu origin, fishers from the East coast. The Rouran supreme rulers used the title of khagan, a popular title borrowed from the Xianbei. The Rouran Khaganate lasted from the late 4th century until the middle 6th century with territories that covered all of modern-day Mongolia and Inner Mongolia, as well as parts of Manchuria in Northeast China, Eastern Siberia, Xinjiang, and Kazakhstan. The Hephthalites were vassals of the Rouran Khaganate until the beginning of the 5th century, with the royal house of Rourans intermarrying with the royal houses of the Hephthalites. The Rouran Khaganate ended when they were defeated by a Göktürk rebellion at the peak of their power, which subsequently led to the rise of the Turks in world history.

Their Khaganate overthrown, some Rouran remnants possibly became Tatars while others possibly migrated west and became the Pannonian Avars (known by such names as Varchonites or Pseudo Avars), who settled in Pannonia (centred on modern Hungary) during the 6th century. These Avars were pursued into the Byzantine Empire by the Göktürks, who referred to the Avars as a slave or vassal people, and requested that the Byzantines expel them. While this Rouran-Avars link remains a controversial theory, a recent DNA study has confirmed the genetic origins of the Avar elite as originating from the Mongolian plains. Other theories instead link the origins of the Pannonian Avars to peoples such as the Uar.

An imperial confederation, the Rouran Khaganate was based on the "distant exploitation of agrarian societies", although according to Nikolay Kradin the Rouran had a feudal system, or "nomadic feudalism". The Rouran controlled trade routes, and raided and subjugated oases and outposts such as Gaochang. They are said to have shown the signs of "both an early state and a chiefdom". The Rouran have been credited as "a band of steppe robbers", because they adopted a strategy of raids and extortion of Northern China. The Khaganate was an aggressive militarized society, a "military-hierarchical polity established to solve the exclusively foreign-policy problems of requisitioning surplus products from neighbouring nations and states."