The Four Heavenly Ministers

Origin of the Four Heavenly Ministers
The Four Heavenly Ministers( 四御 Siyu ), including the Great Jade Emperor ( 玉皇大帝 Yuhuang Dadi ), the Middle Heaven Great Emperor of the North Pole Star of Purple Subtlety ( 中天北極紫微大帝 Zhongtian Beiji Ziwei Dadi ), the Great Heavenly Emperor of the Highest Palace of Polaris ( 勾陳上宮天皇大帝 Gouchen Shanggong Tianhuang Dadi ) and the Imperial God of Earth ( 后土皇地祇 Houtu Huang Diqi ), are four deities in charge of all things in Heaven and Earth under the Three Pristine Ones ( 三清 Sanqing ). The Great Jade Emperor is the master of the ten thousand spirits. The Middle Heaven Great Emperor of the North Pole Star of Purple Subtlety, as the Stellar Sovereign ( 星君 Xingjun ) of the Purple Subtlety Constellation, is situated in Middle Heaven ( 中天 Zhongtian ) and is the master of all the stars. The Great Heavenly Emperor of the Highest Palace of Polaris, which is composed of four stars left of the Imperial Polar Constellation, is located at the Pole Star as the pivot of heaven. The Imperial God of Earth is the center of Heaven and Earth; it had a a male form before the Tang dynasty and acquired a female form during Wu Zetian's reign. Queen Pan of the Song Emperor Zhenzong built a temple on Mt Song for the worship of the Great Holy Earth Queen of Mysterious Heaven ( 后土玄天大聖后 Houtu Xuantian Da Sheng Hou ). Emperor Hui, in the seventh year of the Zhenghe Era, honored the spirit with the title "Imperial Earth Queen Who Receives and Follows Heavenly Laws and Promotes Kind Virtue" ( 承天效法厚德光大后土皇地祇 Chengtian Xiaofa Houde Guande Huang Diqi ). Since then, the Earth Goddess has always been depicted as a female. Since the Song dynasty, owing to the promotion of the Jade Emperor in position and function in the Daoist pantheon, he is often classified in some Daoist scriptures outside of the Four Heavenly Ministers, which are then listed as the Heavenly Emperors of the four poles of the cardinal directions. They are called the North Pole Emperor of Purple Subtlety ( 北極紫微大帝 Beiji Ziwei Dadi ), the South Pole Emperor of Longevity ( 南極長生大帝 Nanji Changsheng Dadi ), the Heavenly Emperor of the Supreme Ultimate ( 太極天皇大帝 Taiji Tianhuang Dadi ), and the East Pole Emperor of Blue Essence ( 東極青華大帝 Dongji Qinghua Dadi ). Contemporary Daoism has returned to the pre-Song identification of the Four Heavenly Ministers.

Functions
The Great Jade Emperor, subordinate only to the Three Pristine Ones, is in charge of the Dao of heaven. The Middle Heaven Great Emperor of the North Pole Star of Purple Subtlety assists the Jade Emperor in administering the longitudes and latitudes of Heaven and Earth, the sun, the moon and stars, as well as the climate of the four seasons. He is honored as the "master of all stars, assistant sovereign of the three realms, correspondent with the Original Vital Breath and inferior only to Great Heaven." The Great Heavenly Emperor of the Highest Palace of Polaris is in charge of the Three Powers ( 三才 Sancai ) of Heaven, Earth and Man, and of wars in the human world. The Imperial Goddess of Earth is in charge of births, land, rivers, and mountains. The Heavenly Emperors of the four poles also have their respective functions. The North Pole Emperor of Purple Subtlety is in charge of all stars; the South Pole Emperor of Longevity is in charge of all spirits; the Heavenly Emperor of the Supreme Ultimate is in charge of the longevity of all spirits; and the East Pole Emperor of Blue Essence is in charge of the salvation of all sentient beings.

Worship in Temples
Besides Halls of the Three Pristine Ones ( 三清 Sanqing ), Daoist temples often have a Hall of the Four Heavenly Ministers ( 四御殿 Siyu Dian ), for the worship of the Four Heavenly Ministers.

In large-scale Daoist rituals, besides the Three Pristine Ones, the Four Heavenly Ministers are also worshipped. Daoist Books say that they are "lined up respectively and honored respectively." Each of the Four Heavenly Ministers has his own divine birthday: The Great Jade Emperor on the 9th of the first lunar month, the Middle Heaven Great Emperor of the North Pole Star of Purple Subtlety on the the 27th of the tenth month, the Great Heavenly Emperor of the Highest Palace of Polaris on the 2nd of the second month, and the Imperial Earth Goddess on the 18th of the third month. Many Daoists go to temples to burn incense on these days. 四御