This kind of sacrifice with military attraction is mostly presided over by officials. In addition to Emperor Taizong's expedition to the Liao Dynasty through Beiyue in the 19th year of Zhenguan, important military and political ministers also went to Beiyue Temple to offer sacrifices and ask for help. The Tang Emperor's sacrifice to Beiyue was also closely related to the rituals of praying for rain and praying for the sun. Hengshan Mountain in the North Mountain is a famous mountain and a great river obviously included in the sacrificial ceremony, and it is the object that must be sacrificed in this area. The sacrifice was presided over by the governor and the monk seat, which fully reflected the official color of praying for rain in Beiyue.
In June of the 14th year of Kaiyuan (726), Emperor Xuanzong of the Tang Dynasty ordered officials to sacrifice mountains and rivers because of the long drought. At that time, he wrote a performance poem for Li Zhe, the messenger of Beiyue, and attributed the effect of rainfall to Xuanzong's sincerity. According to the statistics of the Inscription of Rites and Music Special Sacrifices in the East of Beiyue calendar left over from the Tang Dynasty, from the 9th year of Tang Dali (774) to the 6th year of Tang Xiantong (865), there were 17 special sacrifices in Hengshan Mountain of Beiyue. Except for the sacrificial envoys sent by the central government, most of them were presided over by the assistant of the Ministry of Justice.
At the same time, in different folk belief classes, there are also sacrificial activities to pray for rain and pray for children. At the same time, the worship of Beiyue God and praying for rain are also carried out in different folk belief classes. The reason why the emperors in Tang Dynasty paid so much attention to and even worshipped Hengshan Mountain in Beiyue was related to their worship of Taoism.
For emperors, on the one hand, it is because Taoist fasting ceremony can pray for the blessing and misfortune of rulers and peace in the world; Taoist alchemy and health prescription can satisfy the desire of emperors and nobles to live forever. More importantly, Li Tang used Taoism to create a legal basis for his imperial power. During the Sui and Tang Dynasties, although the gentry rule that prevailed since the Wei and Jin Dynasties declined, their social status and influence were still great. The royal family of the Tang Dynasty came from a humble military family in North Korea, not a noble family.
At the end of Sui Dynasty, Li Yuan and Li Shimin sent troops to fight for hegemony. In order to improve their status and win the support of the upper class, Li Er was honored as the ancestor of the Tang King by taking advantage of the coincidence that Lao Zi, the founder of Taoism, was surnamed Li. They should call themselves immortal Miao descendants, so as to create a public opinion that "God has granted imperial power". In order to win the support of the new rulers for Taoism, some Taoists also created the so-called "Lao Wang Performance" and granted religious myths and prophecies "Fu Ming" to meet the needs of the royal family in the Tang Dynasty.