They were known by the Chinese as the Daxia (大夏, although popular sources have argued that they were in fact the same as the Yuezhi , q.v.), by the Greekss as Tocharoi, and by the Turks as Twghry. A branch of the Yuezhi were the Kushan (q.v.), whose loosely-constituted empire was at its height in the first centuries of the Common Era, and stretched from the Indus Valley to the Aral Sea, embracing much of the route of the Silk Road.
Earlier mummified burials suggest that precursors of these easternmost Indo-European speakers may have lived in the region of Xinjiang and the Karim Basin from around 1000 BC until finally they were assimilated by Uighur Turks in the 8th century CE.
Their late manuscript fragments, of the 7th and 8th centuries, suggest that they were no longer either as nomadic or as barbaric as the Chinese had considered them. Besides the religious texts, the texts include monastery correspondence and accounts, commercial documents, caravan permits, and medical and magical texts. The Kushan Tocharians may have played a part in the transmission of Buddhism to China.
According to a controversial theory, early invasions by Turkic speakers may have been what pushed Tocharian speakers out and into modern Afghanistan, India, Turkmenistan, Pakistan, Tajikistan, and Uzbekistan, and were known as the Kushan
Tocharians, living along the Silk Road, had contacts with the Chinese and Persians, and Turkic, Indian and Iranian tribes. Their Buddhism, like their alphabet, came from northern India. Many apparently also practised some variant of Manichaeanism.