The Hall of Union is situated between the Palace of Heavenly Purity and the Palace of Earthly Tranquility (Kunning Gong), symbolizing the harmony of yin and yang. Architecturally, it resembles the Hall of Central Harmony but is smaller in size.

 

This hall was where the empress hosted banquets during festivals and her birthdays, receiving gifts from concubines, princes’ wives, and princesses [1]. High-ranking consorts, including Imperial Noble Consorts, Noble Consorts, Consorts, Concubines, and other women, would come to the Hall of Union to offer their congratulations to the empress, performing the six-step bowing ritual, which involved three kneelings and three kowtows.

 

This hall also served as the repository for 25 imperial seals, each had a specific function across various domains [2]:

1. Issuing Imperial Edicts and Decrees: Seals such as "Great Qing's Mandate Treasure," "Imperial Seal of the Emperor Receiving Mandate from Heaven," "Imperial Seal of Revering Heaven and Serving the People," "Imperial Edict Seal," "Instructional Decree Seal," and "Imperial Order Seal."
2. For Military Affairs: Seals like "Imperial Military Seal," "Seal of Commanding the Six Armies," and "Seal of Punishing Criminals to Bring Peace to the People."
3. For Judicial Matters: The "Emperor's Precious Treasure" seal.
4. For Religious Activities: The "Son of Heaven's Treasure" seal.

 

These seals were managed by palace supervisors. When needed, the Grand Council had to obtain the emperor's permission before using them.

 

Inside the Hall of Union hangs a plaque inscribed with the characters 无为, meaning “ Non-action” , penned by Emperor Kangxi. These characters are derived from Laozi's saying, "The Dao constantly practices non-action, yet nothing is left undone." Emperor Kangxi wrote these words to admonish future emperors to govern in accordance with the natural order and to show compassion towards the people.

 

To the east of the Hall of Union stands a bronze clepsydra, an ancient timekeeping device that measures time by the flow of water into or out of a vessel. This water clock was constructed in the 10th year of Emperor Qianlong's reign and fell out of use after his dynasty.

 

In the west side of the hall stands a large chiming clock. It was crafted by the Qing Imperial Workshops based on the mechanical principles from western countries. The exterior of the clock is crafted from wood and its structure resembles a traditional Chinese-style, garret-like three-storey wooden cupboard with a height of 5.8 meters. There is a small ladder at the back of the clock used for caretakers to climb up and wind the clock.  In the Qing Dynasty, the time shown by this clock served as the official time standard of the imperial. Though over 2 centuries old, the clock is still in excellent working order.

 

[1]: https://www.beijingtrip.com/attractions/forbidden/celestial.htm

[2]: https://zh.wikipedia.org/wiki/%E4%BA%A4%E6%B3%B0%E6%AE%BF