These nine holy cannons are housed in two
buildings beside the The Nhan and Quang Duc Miradors in the Citadel of Hue.
On January 1st 1803, Emperor
Gia Long ordered all bronze wares of the Tay Son dynasty to be collected and melt into
nine cannons. The work was completed at the end of January 1804. The cannons were named
after the four seasons and the five elements: Metal, Wood, Water, Fire, and Earth. They
are the "Holy Invincible Generals".
Each cannon is 5.10 m long
and weights more than 10 tons. Their barrels are elaborately inscribed with the titles,
position order, weight, instructions, writings on fights against the Tay Son dynasty, and
the collection of bronze wares for casting.
Originally, they were positioned in front
of the Noon Gate, at the foot of the Royal Citadel wall, but they were later moved later
by order of Emperor Khai Dinh to the present-day site.
The cannons have never been used for military purposes and just play a symbolic role as
guardian spirits for the Citadel.