The name ‘China’ (Zhongguo 中國) does not exist as a political entity until Qing dynasty.
One must distinguish cultural subjectivity, geographical location and political entity clearly. Zhongguo was only a term referring to the Han Chinese civilization and its territory (from Canton to Liaodong peninsula and from the East China Sea to Sichuan and Guanxu Provinces) before Qing dynasty. The term Zhongguo is only used as a diplomatic term to address the geographical location instead of the government. When it comes to the government (namely the royal court), the subject must be the dynasty name: Tang, Song, Yuan or Ming.
Manchurian Qing dynasty is the first East Asian regime declaring themselves as Zhongguo. The Treaty of Nerchinsk in 1689 is the first official document addressing an East Asian regime as ‘China’ or Zhongguo. While there is no official Han Chinese version of the treaty, the official Manchurian version of the treaty uses the term Dulimbai gurun (directly translated from Han Chinese term ‘中國 zhongguo’) instead Daicing gurun (Great Qing Empire). Similarly, the official Latin version of the treaty uses the term Imperium Sinicum (Chinese Empire). The official Russian version of the treaty also address the Manchurian emperor as ‘китайского императора’ (Chinese Emperor). In the Latin and Manchurian versions of the treaty, the term ‘Chinese Languages’ (Manchurian: Dulimbai gurun i bithe) is in plural noun, which referred to Han Chinese, Manchurian, Mongolian and other languages. Mark C. Elliott argues that ‘ “China” was no longer simply the territories inhabited by the people of the Central Plain; it became a space, the territories over which the state claimed sovereignty—and which, like other early modern states, it had mapped. In this sense, China’s spatial transformation under the Qing can be said to correspond to the creation of the Chinese geo-body.’ 
Some nationalists stubbornly (and sadly, a few admins of this page) insists that China has been a political entity and a nation for thousands years. However, before the Treaty of Nerchinsk, there is no concept of political entity, and the word China or Zhongguo refers to a much more narrow geographical location and cultural subjectivity.
- Mark C. Elliott, “The Limits of Tartary: Manchuria in Imperial and National Geographies”, The Journal of Asian Studies, Vol. 59, No. 3 (Aug., 2000), p. 638.