The Miaoyuan guan in Peking was founded during the Ming dynasty by Chen Jin, a Vietnamese eunuch captured during the Chinese war against Vietnam in the beginning of the 15th century. After serving four emperors, Chen Jin, who became a Daoist devotee and an expert in the art of long life, reunited his own residence with an old Zhenwu temple next to it, restored the buildings, and founded the Miaoyuan guan dedicated to the Daoist cult. Three centuries later, the Miaoyuan guan became one of the capital residences of the chaplain of the Yongzheng emperor, Lou Jinyuan (1689-1776). Affiliated to the Way of the Heavently Masters, Lou Jinyuan was the abbot of the most important Daoist shrine of the Forbidden City, the Qin'andian and later of the Da Guangming dian and the Dongyue miao ; he was also put in charge of the Bureau of Daoist Registers, the Daolu si. The relation between Lou Jinyuan and the Miaoyuan guan is explained in an inscription written by the official, poet and literary critic Shen Deqian (1673-1769) who, in the same inscription recounts briefly the history of the temple. The article attempts to show, through a particular case, the constant involvement of the eunuchs, the priests and the scholars in the life of Peking's temples, until the 20th century, when the religious activities began to decline.