The Kangxi Emperor (Chinese; pinyin: Kāngxīdì; Wade–Giles: K'ang-hsi-ti; 4 May 1654 – 20 December 1722) is the third emperor of the Manchu-led Qing Dynasty and the second Qing emperor to rule over China proper, from 1661 to 1722.

His reign of 61 years makes him the longest-reigning Chinese emperor in history (although his grandson Qianlong has the longest period of de facto power) and one of the longest-reigning rulers in the world.

However, having ascended the throne aged seven, he is not the effective ruler until later, that role being fulfilled by his four guardians and his grandmother, the Grand Empress Dowager Xiaozhuang.

The Kangxi Emperor is considered one of China's greatest emperors.

He defeats the revolt of the Three Feudatories, forces the Zheng Jing government on Taiwan to submit to Qing rule, blocks Tzarist Russia on the Amur River and expands the empire in the northwest.

He also accomplishes such literary feats as the compilation of the Kangxi Dictionary.

Kangxi's reign brings about long-term stability and relative wealth after years of war and chaos.

He initiates the period known as the "Prosperous Era of Kangxi and Qianlong" which lasts for generations after his own lifetime.

By the end of his reign, the Qing empire controls all of China proper, Manchuria (including Outer Manchuria), part of the Russian Far East, both Inner and Outer Mongolia, and Korea as a protectorate.