The Louguandao 樓觀道 "Way of the Watchout Tower" was an early Daoist school. Its formation goes back to the Northern Dynasties period 北朝 (386~581), and it flourished during the Sui 隋 (581-618) and Tang 唐 (618-907) periods. The patriarch (zushi 祖師) of the Louguan School was Yin Xi 尹喜, the mythical "commander of the Pass" (Guan Yin 關尹), who was a contemporarian of the Daoist Master Laozi 老子. The book Zhuangzi names both side by side.
The alleged teachings of Yin Xi concentrated on the passiveness of the self (zai ji wu ju 在己無居) that followed all outer influences like water flows. In himself, man had to be quiet like a mirror and in his activities responsive like an echo. The Daoist did not have to act as a forerunner (xian ren 先人), but only as a follower (sui ren 隨人).
In the biography of Laozi in the universal history Shiji 史記 it is said that Laozi conceiled his findings about the nature of the Way and did not want to transmit it to others. When he saw the the Zhou dynasty 周 (11th cent.-221 BCE) was in decline, he decided to leave China. Arring at the pass to the west (presumably the Hangu Pass 函谷關), Commander Xi forced Laozi to teach him the secrets of the Dao, so that Xi would be able to write them down. The result of Laozi's lecturing Commander Xi was the two-chapters long book Daodejing 道德經.
The book Liexianzhuan 列仙傳 reports of Guan Yin's studies of the "inner teachings" (neixue 内學) and his ability to consume the "essence of the flower" (jinghua 精華) in which he excelled even before Laozi arrived at the pass. The Commander's cultivation of the Dao was apparently a precondition for Laozi's willingness to introduce him into the mystery of the Dao. Guan Yin accompanied Laozi in his journey to the west and took part in the conversion of the barbarians (hua hu 化胡). Nothing was known about his further life and the time of his death.
Yin Xi's own book was called Guanyinzi 關尹子 or Guanlingzi 關令子 and had a length of nine chapters. This is the basic story about Yin Xi as it had developed until the end of the Han period. This story was later expanded, especially in episodes describing the transformation of Laozi to the Buddha. Such stories can be read in the Western Jin period 西晉 (265-316) book Laozi huahu jing 老子化胡經 by Wang Fu 王浮, or the stories Xuanmiao neipian 玄妙内篇, Chusai ji 出塞記, Guanling Yin Xi zhuan 關令尹喜傳 and Wenshi neizhuan 文始内傳 from the Eastern Jin 東晉 (317-420) and Southern Dynasties 南朝 (420-589) periods.
Yin Xi plays in these stories the role of Laozi's disciple. His watchout tower (louguan 樓觀), gave this branch of Daoism its name. This building, or rather hut, is said to have been made of grass, with the roof (partially) open to allow observation of the stars and the sky, as the biographies Louguan xianshi zhuan 樓觀先師傳 and Louguan benji 樓觀本記 tell.
It is also said that Yi Xi was appointed a grand master (dafu 大夫) under King Kang 周康王 of the Zhou dynasty. After he had left China together with Laozi, King Mu 穆王 had a shrine erected on the place where the hut had been. Daoist practitioners assembled there and founded a temple and the Louguan School.
In fact, this school only emerged during the Southern Dynasties period. The story of its origin in the glorious past was invented in order to boost its image. A line of transmission was also constructed that spoke of a whole series of patriarchs of the late Zhou and the Qin 秦 (221-206 BCE) period, like Yin Gui 尹軌, Du Chong 杜沖, Peng Zong 彭宗, Song Lun 宋倫, Feng Zhang 馮長, Yao Tan 姚坦, Zhou Liang 周亮, Yin Cheng 尹澄, Wang Tan 王探, Li Yi 李翼, Feng Heng 封衡, and Zhang Hao 張皓.
The Louguan Temple is historically verifiable in the 3rd century CE, when it was headed by a certain Master Zheng (Zheng Lüdao 鄭履道). His disciple Liang Chen 梁諶 (248-318) was active during the Western Jin period. Under the Eastern Jin dynasty 東晉 (317-420), the community was headed by Wang Jia 王嘉, Sun Che 孫徹 and Ma Jian 馬儉 (342-439). Its social importance and political influence was quite low. Only under Emperor Taiwu 北魏太武帝 (r. 423-451) of the Northern Wei 北魏 (386-534) it entered the orbit of the imperial court, and Yin Tong 尹通, Niu Wenhou 牛文侯 (458-539) and Yin Fa 尹法 won some adherents, so that in the mid-6th century, the Lougan School numbered some 40 masters. Under Emperor Xiaowen 北魏孝文帝 (r. 471-499) the Daoist master Wang Daoyi 王道義 (448-510) from Mt. Gushe 姑射山 decided joining the Louguan School. The temple had to be enlarged, and its library of Daoist writings expanded considerably. Master Chen Baochi 陳寳熾 (468-544) was called to the court to instruct the emperor in The Yanying Hall 延英殿, where he won over the Duke of Anding 安定公 and many high ministers. After his death in 549 Li Shunxing 李順興 was allowed to preach at the court.
The core of the Louguan Canon was, of course, the book Daodejing, but also the writings Laozi huahu jing, Laozi xisheng jing 老子西升經, Laozi kaitian jing 老子開天經, and Miaozhenjing 妙真經 belonged to the most-used writings of the Louguan liturgy.
Adherents of the Louguan School also used several writings of the Shangqing Tradition 上清派, like Dadong zhenjing 大洞真經, Huangting neijing jing 黄庭内景經, Shangqing qiongwen di zhangjing 上清瓊文帝章經, Taishang suling dongxuan da youmiao jing 太上素靈洞玄大有妙經, Taishang yinshu 太上隱書 or Lingshu ziwen 靈書紫文. Several texts of the Lingbao School 靈寳派 were also used in the Louguan Tradition.
In the field of practice, as self-cultivation and alchemy, the Louguan Tradition made selective use of methods used by other schools. Such were talismans (fulu 符籙) or sublimation pots (danding 丹鼎). Liang Chen, for instance, "ate breath", "devoured talismans" (shi qi tun fu 食炁吞符) and consumed cinnabar (dansha 丹砂). Ma Jian used prognostication methods of the dunjia type (dunjia zhanhou 遁甲占候). He did not consume grains, but instead certain materia medica(fu yao 服葯), and practiced the circulation of breath (xing qi 行氣) and "gymnastics" (daoyin 導引). Above all, he was able to attract good and dispel evil spirits. Yin Tong ate for decades just Polygonatum herbs (huangjing 黄精) and realgar minerals (xionghuang 雄黄). He was also famous as a healer. The most common practice of the Louguan Tradition was the consumption of certain plants.
The master Wang Yan 王延 (fl. 537), courtesy name Wang Ziyun 王子元, became one of the most prominent Daoist leaders of the Louguan School in the mid-6th century. Under his guidance, a new Louguan Temple imitated the structure of earlier, successful places of veneration, such as the Yuntai Monastery 雲臺觀 on Mt. Huashan 華山. Wang made the Maoshan master Qiao Kuang 焦曠 his teacher, from which he took ideas from the scripture Sandong bijue zhenjing 三洞祕訣真經 "True scripture of the secret formulas of the Three Caverns". Emperor Wu 北周武帝 (r. 560-578) of the Northern Zhou 北周 (557-581) summoned him to the court for instruction. When Emperor Wu prohibited Buddhism and various schools of Daoism, he had concurrently built the Tongdao Temple 通道觀, in which Wang Yan was expected to teach and to comment on the book Sandong jingtu 三洞經圖 "Illustrated scripture of the Three Caverns". He also wrote the Sandong zhunang 三洞珠囊 "Pearl bag of the Three Caverns".
With the foundation of the Sui dynasty, the Xuandu Temple 玄都觀 was built, to which Wang Yan and his school were consequently transferred. Emperor Wen 隋文帝 (r. 581-604) carried out the great purification rites (zhihui dajie 智慧大戒), and the high ministers Su Wei 蘇威 (542-623) and Yang Su 楊素 (544-606) were also instructed by the great Louguan master. Wang Yan died in 604.
Another great master of that period was Yan Da 嚴達 (515-609), courtesy name Daotong 道通, who was a disciple of Hou Kai 侯楷. When Emperor Wu of the Northern Zhou planned to prohibit Daoism, it was Yan Da who convinced the emperor that the native religion of Daoism should prevail over Buddhism. The latter would alienate the people from each other, while the former would protect the country. Emperor Wu therefore allowed Daoism was to survive, but its priests were banned to a temple far from the capital. He selected Buddhist and Daoist worthies to live and teach there, for the sake of the state. These were Yan Da, Wang Yan, Su Daobiao 蘇道標 (fl. 572-583), Cheng Faming 程法明, Zhou Huasheng 周化生, Wang Zhenwei 王真微, Shi Daole 史道樂, Yu Zhang 于章, Zhang Facheng 張法成 and Fu Daochong 伏道崇. Emperor Wen of the Sui dynasty allowed the Louguan Temple to be revived.
All Daoist schools experienced the support of the Tang dynasty because its family had the same surname like Laozi, namely Li 李, and therefore venerated this saint of Daoism also as the dynastic patron. The Louguan master Qi Hui 岐暉 (557-630), courtesy name Pingding 平定, had even been an adherent of Li Yuan 李淵 (i.e. Emperor Gaozu 唐高祖, r. 618-626) before the latter founded the Tang dynasty. Li Yuan granted large tracts of land to the Louguan Temple and bestowed it the new name of Zongsheng Temple 宗聖觀. In 624 the emperor personally visited the temple and performed sacrifices to Laozi. In 630 Yin Wencao 尹文操 (622-688) was appointed head of the Louguan/Zongsheng and the Haotian 昊天觀 temples. Yin Wencao wrote the book Xuanyuan huangdi shengji 玄元皇帝聖紀, which he submitted to the thone. Emperor Gaozong 唐高宗 (r. 649-683) was delighted by the text and bestowed upon the author the honorific title of Grand Master of Splendid Happiness (guanglu dafu 光祿大夫) and *non-resident Junior Chamberlain for Ceremonials (xing taichang shaoqing 行太常少卿). Yin was also the author of the texts Quhuolun 祛惑論, Xiaomolun 消魔論 and a revised version of the biographical collection Louguan xianshi zhuan 樓觀先師傳, in which he tried to eliminate Buddhist elements.
With the support of the imperial house of the Tang dynasty the Louguan School was able to attract numerous believers among the upper levels os society. After the An Lushan 安祿山 rebellion and the decline of the central government, the school gradually lost its importance to various other Daoist schools. It vanished in the 10th century. In 988 Emperor Taizong 宋太宗 (r. 976-997) of the Song dynasty 宋 (960-1279) renamed the Louguan Temple (or the Zongsheng Temple, respectively) Shuntian Xingguo Temple 順天興國觀. It was destroyed in 1234 and rebuilt under the auspices of the new Quanzhen School 全真道, the Daoist school which was protected by the Yuan dynasty 元 (1279-1368). Consequently, the site was transformed into a temple of this school.