What are the Four Guardians of Thang Long and when were they formed?
The Four Guardians of Thang Long (Tu tran Thang Long) are four temples guarding the four directions of the old Thang Long capital: Bach Ma Temple in the East, Voi Phuc Temple in the West, Kim Lien Temple in the South, and Quan Thanh Temple in the North. This system was not an official regulation from the founding of the capital, but is regarded by researchers as a tradition gradually built and completed over many centuries.
According to VietnamPlus, the term "Thang Long Tu tran" appears in written documents very late, in 1956, in Dang Xuan Khanh's book "Thang Long co tich khao tinh hoi do." The book records two lines of Han characters listing: "Thang Long Tu tran. East guardian Hang Buom Bach Ma dai vuong tu. West guardian Thu Le Linh Lang dai vuong tu. South guardian Kim Lien Cao Son dai vuong tu. North guardian Tay Ho Tran Vu dai de tu." Earlier, the term "Tu tran tu" had appeared in the document "Ha thanh linh tich co luc" dating to the Nguyen era, with similar records of four temples in four directions.
Why is it called "tran"?
The word "tran" in Tu tran means to guard, to block disasters from outside from entering the capital. Dr. Nguyen Doan Minh, Acting Head of the Historical and Cultural Research Division at the Institute for Imperial Citadel Studies, explains that the Four Guardians protecting Thang Long carries the meaning of guarding, preventing natural disasters and enemy threats, helping people's lives remain peaceful. More deeply, the peace of the capital is also the endurance of the Dai Viet nation.
Is Hoan Kiem Lake part of the Four Guardians of Thang Long?
Hoan Kiem Lake, also called Ho Guom, is not in the list of the four guardian temples of Thang Long. This needs to be stated clearly from the start, because many people confuse the famous spiritual sites of Hanoi. The Four Guardians are four temples worshiping four deities who protect the capital in the four directions East, West, South, North, while Hoan Kiem Lake is a scenic site at the center of the capital, tied to the legend of King Le Loi returning the magic sword.
Even so, Hoan Kiem Lake still holds a special role in the spiritual layout of Thang Long. If the Four Guardians form a protective ring in four directions, Hoan Kiem Lake sits at the center, like a spiritual anchor in the heart of the capital. These two layers do not replace each other but complement each other: one is a feng shui defense system, the other is a symbol of righteousness and peace.
Does the Hong Duc map mention Hoan Kiem Lake?
According to VietnamPlus, the Hong Duc era map commissioned by King Le Thanh Tong, completed in 1490, depicts the Thang Long capital with many place names such as Kinh Thien Palace, Doan Mon, Dong Cung, Thai Mieu, Phung Thien prefecture, Hoan Kiem Lake, Quoc Tu Giam, Nam Giao altar, West Lake, Khan Son mountain, Giang Vo, Bao Khanh gate, and To Lich River. In this map, the three temples Bach Ma, Linh Lang, and Quan Tran Vu were positioned in the East, West, and North of Thang Long respectively. Kim Lien Temple in the South does not yet appear in this map, but documents state that by 1772 at the latest the temple was present at its current location.
Thus, Hoan Kiem Lake and the Four Guardian temples coexist in the sacred space of Thang Long, but belong to two different structural layers. Hoan Kiem Lake is a natural site tied to legend, while the Four Guardians are a temple system positioned by the four directions.
How is the legend of the returned sword tied to Hoan Kiem Lake?
The legend of the returned sword tells that King Le Loi, after driving out the Ming invaders, was one day on a dragon boat on the lake when a golden turtle surfaced and said: "Please, Your Majesty, return the sword to the Dragon King." The king returned the magic sword, and the golden turtle took the sword in its mouth and dove underwater. Since then the lake has been called Hoan Kiem Lake, meaning the lake of the returned sword.
This story carries several layers of meaning. First, it affirms the righteousness of the Lam Son uprising: the magic sword was given by a supernatural power, used only to drive out invaders, and once the country was at peace it had to be returned. Second, it ties Le Loi's victory to a specific site at the center of the capital, turning Hoan Kiem Lake into a place preserving the memory of the transition from war to peace. Third, it places Hoan Kiem Lake at the center of Thang Long's spiritual layout, where both historical and mythical elements converge.
Why is the legend of the returned sword not part of the Four Guardians?
The legend of the returned sword is not part of the Four Guardians because the Four Guardians are a system of temples worshiping deities who protect the capital in four directions, while the legend of the returned sword is tied to a specific historical event and a natural site. The deities in the Four Guardians such as Bach Ma, Linh Lang, Cao Son, and Tran Vu all had merit in helping dynasties defeat enemies, ward off evil, and strengthen the throne, as recorded by VietnamPlus. Meanwhile, the legend of the returned sword is not tied to any deity worshiped at any temple in the Four Guardian system.
However, both share a common pattern: the intervention of supernatural forces in the fate of the nation. If the Four Guardians express belief in the constant protection of deities over the capital, the legend of the returned sword expresses belief in divine support at decisive moments of history.
Who do the four guardian temples worship and where are they?
The table below summarizes basic information about the four temples in the Thang Long Four Guardian system according to VietnamPlus and Nhan Dan newspaper:
| Direction | Temple name | Location | Deity worshiped |
|---|---|---|---|
| East | Bach Ma Temple | 76 Hang Buom, Hang Buom ward, Hoan Kiem district | Bach Ma dai vuong, also known as Long Do deity, the deity governing Dai La citadel, granted the title Quoc do Thanh hoang dai vuong |
| West | Voi Phuc Temple | Thu Le, Ba Dinh district | Linh Lang dai vuong |
| South | Kim Lien Temple | Kim Lien, Dong Da district | Cao Son dai vuong |
| North | Quan Thanh Temple | Tay Ho, Ba Dinh district | Tran Vu dai de |
What is special about Bach Ma Temple?
Bach Ma Temple was built earliest among the Four Guardians, tied to King Ly Thai To building the Thang Long citadel, according to Nhan Dan newspaper. Legend tells that when King Ly Cong Uan established the capital and built Thang Long, wherever he built, the ground collapsed. The king prayed to Long Do, the deity governing Dai La citadel. The deity manifested as a white horse, and the king followed the horse's hoof prints to build, and the citadel no longer collapsed. When the citadel was finished, the king granted Long Do the title Quoc do Thanh hoang dai vuong, the guardian deity of the capital. Bach Ma Temple still preserves many precious artifacts, including 18 ancient stone steles, 17 royal edicts from the Nguyen era, and a large wooden white horse.
What roles do the remaining temples have?
Voi Phuc Temple worships Linh Lang dai vuong, a deity who helped the dynasty defeat enemies. Kim Lien Temple worships Cao Son dai vuong, a deity tied to high mountains and protection of the southern land. Quan Thanh Temple worships Tran Vu dai de, the deity guarding the North, as recorded in VietnamPlus documents: "Quan Tran Vu in the north of the citadel is to guard the north." All four temples had merit in helping contemporary dynasties defeat enemies, ward off evil, and strengthen the throne.
In what context were the Four Guardians of Thang Long created?
According to research by Dr. Nguyen Doan Minh, "Tu tran Thang Long" or "Thang Long Tu tran" is an "invention/construction of tradition." Confucian scholars under the Nguyen dynasty constructed this tradition in the historical context of Hanoi under the Nguyen court, when Vietnam's last feudal dynasty was in decline and the country suffered under French colonial oppression.
VietnamPlus documents list four factors as the basis for this construction. First, the sacred space of Thang Long had been established about 800 years earlier. Second, the deities at the four temples all had merit in helping contemporary dynasties defeat enemies, ward off evil, and strengthen the throne. Third, documentary evidence related to the formation of the Four Guardian concept existed earlier, such as the Hong Duc map and records of King Le The Tong (1573-1599) ascending the throne, granting titles to deities, and calling Linh Lang Temple a guardian of the capital. Fourth, belief in the feng shui elements of the Thang Long capital, since each time the capital moved away from Thang Long, the country fell into dependency and lost sovereignty.
Why is the number 4 important in the spiritual layout?
According to Assoc. Prof. Dr. Nguyen Ngoc Oanh, Head of the International Relations Faculty at the Academy of Journalism and Communication, the number 4 symbolizes the best things, used by ancestors as a balance and fullness of heaven and earth. A year has four seasons, the land has four directions, the number 4 creates a square symbolizing solidity, stability, and peace. Dr. Nguyen Doan Minh also lists many symbols of the number 4 in Vietnamese culture: Tu bat tu, Tu phu, Tu Phap, An Nam tu dai khi. The Four Guardians protecting Thang Long carry the same meaning: the guarding helps the capital avoid natural disasters and enemy threats, thereby helping people's lives remain peaceful.
Where does Hoan Kiem Lake stand in the spiritual layout of Thang Long?
Hoan Kiem Lake stands at the center of Thang Long's spiritual layout, not part of the Four Guardian ring but holding the role of a spiritual anchor. If the Four Guardians are four temples guarding the four directions, Hoan Kiem Lake is where the memory of the transition from war to peace is preserved, tied to the legend of King Le Loi returning the magic sword.
One can picture Thang Long's spiritual layout as two structural layers. The first layer is the four-direction protective ring with the four guardian temples, focused on feng shui guarding and protecting the capital from natural disasters and enemy threats. The second layer is the central sites tied to legends and historical events, of which Hoan Kiem Lake is a typical example, focused on symbolism and memory preservation. These two layers coexist, complement each other, and create the distinctive sacred space of Thang Long.
Why is Hoan Kiem Lake not classified among the Four Guardians?
Hoan Kiem Lake is not classified among the Four Guardians because the Four Guardians are a system of temples worshiping four deities who protect the capital in four directions, while Hoan Kiem Lake is a natural site tied to the legend of the returned sword. The deities in the Four Guardians are all deities worshiped at temples, with merit in helping dynasties defeat enemies, ward off evil, and strengthen the throne. Meanwhile, Hoan Kiem Lake is not tied to any deity worshiped at any temple in the Four Guardian system, but to a specific historical event and a legend about a golden turtle returning the sword.
However, this does not diminish Hoan Kiem Lake's role in Thang Long's spiritual layout. On the contrary, precisely because it sits at the center and is not part of the four-direction temple system, Hoan Kiem Lake holds an independent position, both a historical witness and a cultural symbol. In the Vietnamese mind, Hoan Kiem Lake and the Four Guardians together shape the image of a Thang Long with historical depth and spiritual depth.
Do research schools agree on the Four Guardians?
Researchers do not fully agree on the formation time and nature of the Four Guardians of Thang Long. Some opinions hold that the Four Guardian structure existed much earlier than the term, based on evidence from the 1490 Hong Duc map, in which the three temples Bach Ma, Linh Lang, and Tran Vu were positioned in the East, West, and North. Other opinions, notably Dr. Nguyen Doan Minh's research, emphasize that the term "Tu tran" appears in written documents very late and carries the character of "constructing tradition" in the historical context of the Nguyen era.
This difference is not an absolute contradiction. It can be understood that the temples had existed for a long time, but systematizing them into a set of four temples guarding four directions was a later process, tied to the need to affirm Hanoi's identity and sacred space in a special historical context. This article does not offer a final conclusion on that issue, but only presents existing viewpoints for readers' reference.
Conclusion
Hoan Kiem Lake is not part of the Four Guardian system of Thang Long, but the legend of the returned sword tied to the lake holds a central role in the spiritual layout of the capital. The Four Guardians are a four-direction protective ring with four temples worshiping four deities who had merit with the capital. Hoan Kiem Lake is the spiritual anchor at the center, where the memory of the transition from war to peace is preserved. Together they create the distinctive sacred space of Thang Long, a space that both guards feng shui and carries deep cultural symbolism.
