The Tiananmen Gate to the Forbidden City was built in 1415 during the Ming Dynasty. Towards the demise of the Ming Dynasty, heavy fighting between Li Zicheng and the early Qing emperors damaged (or perhaps destroyed) the gate. The Tiananmen square was designed and built in 1651, and has since enlarged four times its original size in the 1950's.
British and French troops who invaded Beijing in 1860 pitched camp near the gate and briefly considered burning down the gate and the entire Forbidden City. They decided ultimately to spare the palace and to burn instead the emperor's Old Summer Palace.
The Qing emperor eventually agreed to let the foreign powers barrack troops – and later establish diplomatic missions – in the area, resulting in the Legation Quarter immediately to the east of the modern square.
During the Boxer Rebellion of 1900 the siege badly damaged the office complexes and several ministries were burnt down. In the conflict's denouement, the area became a space for foreign troops to assemble their armies and horses.