Tannu Uriankhai (Tuvan: Таңды Урянхай, [taŋˈdɤ urʲanˈχaj]; Mongolian: Тагна Урианхай, romanized: Tagna Urianhai, [ˈtʰaɢəɴ ʊrʲæŋˈχæɪ̯];[1] simplified Chinese: 唐努乌梁海; traditional Chinese: 唐努烏梁海; pinyin: Tángnǔ Wūliánghǎi) was a historical region of the Mongol Empire, its principal successor, the Yuan dynasty, and later the Qing dynasty.

The territory of Tannu Uriankhai largely corresponds to the modern-day Tuva Republic of the Russian Federation, neighboring areas in Russia, and a small part of the modern state of Mongolia.

Tannu designates the Tannu-ola Mountains in the region, and Uriankhai was the Mongolian name for the Tuvans (and accordingly their realm), which meant "the people living in the woods" (Chinese: 林中百姓; pinyin: Línzhōng Bǎixìng).

[4][5] With the fall of the Yuan dynasty in China, Tannu Uriankhai was controlled by the Oirats (western Mongols, also known as Zungars)[citation needed] until the end of the 16th and early 17th centuries.

In the latter half of the 18th century, the magistrate of Tannu Banner was placed in charge of the others as governor ("amban-noyon", 四旗總管) in recognition of his military service to the dynasty, until 1872.

If Qing statutes rigorously defined procedures to be followed by the nobles of Outer and Inner Mongolia, Zungaria, and Qinghai for rendering tribute, receiving government stipends, and participating in imperial audiences, they were silent regarding Tannu Uriankhai.

The Qing military governor at Uliastiai, on his triennial inspection tours of the 24 pickets under his direct supervision, never crossed the Tannu-ola mountains to visit Uriankhai.

Instead, a few days were set aside for trade at Uliastai when Uriankhai nobles delivered their annual fur tribute to the military governor and received their salaries and other imperial gifts (primarily bolts of satin and cotton cloth) from the emperor.

[14] The formal beginning of Russian colonization in Tannu Uriankhai occurred in 1885 when a merchant received permission from the governor-general of Irkutsk to farm in present-day Turan.

There were rumors of fabulous wealth to be gained from this area, and the Russian provincial authorities at Yeniseisk were inundated with petitions from gold miners to mine, and permission to do was granted.

Over the years the office quietly but steadily claimed the power of government over at least the Russians in the region—taxation, policing, administration, and justice—powers that should have belonged to but were effectively relinquished by the Qing.

[14] Shortly after the office of Superintendent was created, the Sibirskaya gazeta brought out a special edition, congratulating the government on its creation, and predicting that all Tannu Uriankhai would someday become part of the Russian state.

If repayment were not forthcoming, Russian merchants would drive off the livestock of either the debtor or of his relatives or friends, which led to retaliatory raids by the Uriankhai.

For many reasons—more aggressive selling, easier credit terms, cheaper and more popular goods for sale—the Han people soon dominated commerce just as they had in Outer Mongolia.