There is no easy way to explain how the Manchus, with a population about one million, could by 1644 seize the throne of China. They had devised a writing system for their spoken language only in 1599. Their "banner system," which gave their tribal organization a bureaucratic touch by regulating the mobilization procedure and its agricultural support, came into existence no earlier than 1601. In 1635 they began to call themselves Manchus. Another year lapsed before the Qing dynasty was formally proclaimed. It took less than a half century for this loosely constructed confederation of tribes to elevate itself to be the governing body of an enormous empire with a profound cultural heritage.
The Qing conquest of China differed from the experience of previous alien dynasties. Earlier invaders took advantage of China's disunity to become one of the contenders. They gained a foothold inside the Great Wall and governed a mixed population before moving south. The Manchus took China from the outside in one sweep.
In early 1644, peasant leader Li Zicheng entered Beijing through its back door. He occupied the high points along the Great Wall and took the area of the imperial tombs before descending to the capital. Hours before Li broke through the defenses of the inner city, Emperor Zhu Youjian hanged himself. His last testimony declared: "Bandits, I invite you to quarter my body, but I forbid you to do harm to my subjects,