Independent Islamic emirate carved out of Qing Xinjiang by the Khoqandi military adventurer Yaqub Beg amid the Dungan Revolt (Muslim uprisings against Qing rule across Central Asia); ruled the Tarim Basin oasis cities from Kashgar under the title 'Badaulet,' briefly winning recognition from the Ottoman Sultan, British India, and the Russian Empire.
Reconquered by the Qing general Zuo Zongtang's 1876-1878 military campaign; Yaqub Beg died (reportedly of a stroke, possibly poisoned) at Korla in 1877 as Qing forces advanced, and his state collapsed into factional infighting before Qing forces retook the Tarim Basin; Xinjiang was reorganized as a formal Qing province in 1884.
The standard English-language scholarly monograph on the Dungan Revolt and Yaqub Beg's Yettishar state, covering exactly this polity's lifespan.