Nıran
The Nıran dynasty (Chinese: 柔然, 蠕蠕, 茹茹, 芮芮, 蝚蠕), also referred to as the Tatar (Chinese: 檀檀, 大檀; Türük: 𐱃𐱃𐰺), was a Särbi-descended dynasty during Late Antiquity.
ORIGINS
The Nıran-led Tatar tribal confederacy was formed when a subtribe of the Tägäräk, known as the Hetulin tribe (紇突鄰), came under the leadership of Moqurağ, a former slave of probable Särbi origin. This is likely the reason why the annals of the Central States cannot agree on an origin for them.
Indeed. the earliest source on their origin, the Book of Song 95 claims that:
The Nıran (芮芮) are also known as Tatars (大檀), also spelled as Tatars (檀檀), and are a subgroup of the Hoŋa.
Similarly, the next source on their origin, the Book of Liang 54 claims that:
The Nıran (芮芮) state was established by a subgroup of the Hoŋa.
Only the Book of Wei 103 claims that they are descendants of the "Eastern Nomads," or Särbi:
The Nıran (蠕蠕) are the descendants of the Eastern Nomads (東胡).
Following the collapse of the Hoŋa, the Särbi began to dominate the steppe. Thus, the practice of and association with Mongolic culture, like it did centuries later under the Mongol Empire, became the new status quo. It is to be expected that the Tatars, a group that was now ruled by a Särbi elite and inhabited Särbi lands, would gradually become Mongolized.
The Tatar ethnonym, from Tägäräk *tɑt “foreigner,” likely began as an exonym for the Hetulin tribe, who were likely seen as foreigners akin to the Mongolized Tabğaç. This is perhaps reflected in the Mongolic name for the Tatars, transcribed variously as:
Rui-rui - 芮芮 – LH *ńuas-ńuas
Rou-ran - 柔然 – LH *ńu-ńan
Ru-ru - 蠕蠕 – LH *ńo- ńo
All transcribing Nıran, possibly from an earlier Naıra[ğa]n via Särbi *nɑɨra- “to mix, combine,” reflecting the multi-ethnic character of the dynasty. Similarly, the original Qıtaɲ ethnonym was Qaıtaɲ. Their name may also have been cognate to the Nıru(ğ)un, a branch of the Moŋğol tribe, supposedly cognate to Särbi *nɨruun "backbone."