Under the previous Sui dynasty, ‘four direction’ mirrors had become popular with portraying four lions south, east, west and centre. Under the Tang, these acquired an individual identity:
Azure Dragon (青龙) is a symbol of the East and represents the element of wood and the season of spring. It is associated with growth, renewal, and vitality.
Vermilion Bird (朱雀) represents the South and is linked to the element of fire and the season of summer. This mythical bird symbolizes warmth, passion, and energy.
White Tiger (白虎) symbolizes the West and is associated with the element of metal and the season of autumn. It represents strength, courage, and protection.
Black Tortoise (玄武) is actually a combination of a tortoise entwined with a snake and represents the North. It is linked to the element of water and the season of winter, symbolizing endurance, stability, and protection.
Together these four animals embody cosmic balance and harmony. Their presence on bronze mirrors not only served a decorative purpose but also conveyed deeper symbolic meanings related to the natural world and cosmology.