TL;DR: Thần chủ is a wooden tablet, made of jujube wood, with the family name and title in the center and birth and death dates on either side, kept inside a closed square box. Custom books record that a household honors four generations (cao, tằng, tổ, khảo); at the fifth generation the cao tổ tablet is buried and the lower ranks move up one step, a practice called ngũ đại mai thần chủ. The thủy tổ shrine keeps a tablet honored permanently, called bách thế bất điêu chi chủ.
What is a thần chủ, and why is it called ngũ đại mai thần chủ?
Thần chủ is a wooden tablet recording the family name, title, and birth and death dates of a deceased person, placed on the altar for descendants to honor. According to the rule recorded in custom books, a household keeps the thần chủ of four generations counted from the household head, namely cao, tằng, tổ, khảo; at the fifth generation the cao tổ tablet is buried, a practice called ngũ đại mai thần chủ.
Toan Ánh (2001) records this term in Phong tục thờ cúng tổ tiên trong gia đình Việt Nam: thần chủ are kept for only four generations and below, and when the fifth generation comes the cao tổ tablet is buried, the tằng, tổ, and khảo ranks move up one step, and the newly deceased takes the place of the khảo tablet[1]. Song Mai and Quỳnh Trang (compilers, 2006) in Phong tục thờ cúng của người Việt record the same rule and add: "Ngũ đại mai thần chủ means the thần chủ is buried at the fifth generation"[2].
It should be said clearly: this is the rule of Confucian family rites as described in the books, not a regulation binding every household. The books cited all describe the custom of the Kinh people, mainly in the northern delta, from roughly the early to the late 20th century; they do not extend it to the central or southern regions, to other ethnic groups, or to the present day where the books say nothing.
What is a thần chủ made of, and what is written on it?
Thần chủ is made of jujube wood, because folk belief holds that the jujube tree lives a thousand years[1][3]. The dimensions given in the books are not consistent: Toan Ánh (2001) and Bùi Xuân Mỹ (2001) both record a length of about two tấc rưỡi[1][3], while Song Mai and Quỳnh Trang (2006) record "about two phân rưỡi"[2]. The sources conflict here, so the figures are noted without asserting which is standard.
As for the content written on the tablet, Toan Ánh (2001) records: the center gives the family name and title; the two sides give the birth and death dates of the ancestor[1]. Bùi Xuân Mỹ (2001) describes it similarly and adds that the thần chủ has a square box covering it, kept in a long alcove, opened only for worship and sacrifice[3]. Song Mai and Quỳnh Trang (2006) record the two sides as the date and hour of birth and death[2].
On ritual objects in general, Bùi Xuân Mỹ (2001) notes that common households used jackfruit wood, while wealthy households used bronze[3].
Why honor four generations and then bury the tablet?
The books cited do not explain the reason for the four-generation rule, only recount the practice. Toan Ánh (2001) writes: "In family shrines, once thần chủ are established there must be tablets for four generations and above, counted from the household head. These are the tablets of the kỵ, cụ, ông, and cha, that is cao, tằng, tổ, khảo"[1]. Song Mai and Quỳnh Trang (2006) likewise record the rule without giving a basis[2].
Therefore any current explanation of the meaning of the numbers four and five is speculation by later writers, not something the books cited say. This article does not offer a reason in place of the books.
The thủy tổ exception: bách thế bất điêu chi chủ
The thủy tổ shrine of a lineage has its own tablet honored permanently without change. Phan Kế Bính (1915) in Việt Nam phong tục records: "The Thủy-tổ shrine has its own thần-chủ, honored forever, never changed, called 'Bách thế bất diêu chi chủ'"[4]. These are Hán characters meaning the thủy tổ tablet is never moved.
Toan Ánh (2001) also records this rule at the lineage altar: the thủy tổ tablet usually states clearly which lineage's thủy tổ it is, and "this thần chủ is never changed, hence called bách thế bất điêu chi chủ"; the book also notes that today many people use the Romanized script to inscribe tablets[1]. Thus the four-generation rule applies to family altars, while the thủy tổ tablet in the lineage shrine stands outside that rule.
Table: the ranks in the household shrine and how long they are honored
| Rank | Name | How long honored | Source |
|---|---|---|---|
| 1 | Khảo (father) | Until a newly deceased takes the place | Toan Ánh (2001)[1] |
| 2 | Tổ (grandfather) | Moves up one step at the fifth generation | Toan Ánh (2001)[1] |
| 3 | Tằng (great-grandfather) | Moves up one step at the fifth generation | Toan Ánh (2001)[1] |
| 4 | Cao (great-great-grandfather) | Buried at the fifth generation | Toan Ánh (2001)[1] |
| Thủy tổ | Bách thế bất điêu chi chủ | Honored forever without change | Phan Kế Bính (1915)[4] |
The table summarizes the rule as recounted in the books; it is not a legal regulation or a mandatory custom. Bùi Xuân Mỹ (2001) also records the four-generation rule and the burial of the cao tổ tablet at the fifth generation[3].
Does a photo altar need a thần chủ?
The books cited do not mention a photo altar or honoring photographs in place of a thần chủ, so it cannot be concluded whether a photo altar needs one. They describe only an altar with a wooden thần chủ, kept in a long alcove, opened for worship and sacrifice[1][3].
What the books do say is the scope of application: Toan Ánh (2001) notes that "among ordinary families, few households keep thần chủ", and where the thần chủ alcove is placed there is a bench or throne symbolizing the presence of the ancestors[1]. Thus even in the society the books describe, not every household established thần chủ. This is where readers today often err: the thần chủ is one of the ritual objects of a household that has established a family shrine, not something required for every altar.
What stands beside the thần chủ on the altar?
The thần chủ does not stand alone. Phan Kế Bính (1915) describes wealthy households with a family shrine honoring cao, tằng, tổ, khảo at the central altar; on the side altars are honored Thổ công, Táo quân, and Nghệ sư; common households without a separate shrine honor at their own home, and "however poor, there is still an altar"[4].
Bùi Xuân Mỹ (2001) lists other ritual objects on the incense table: a single vase or a pair of vases for peach branches at Tết, flowers on giỗ chạp days, and a fruit tray displayed at offerings[3]. These details show that the thần chủ is one part of the system of ritual objects, not the whole altar.
The gia phả kept alongside the thần chủ
Beside the thần chủ, the shrine also keeps the gia phả. Toan Ánh (2001) records that the gia phả is a book recording the order of ancestors and all members of the household, each with birth and death dates, titles, sometimes temperament and preferences in life, along with the senior and junior branches[1]. Song Mai and Quỳnh Trang (2006) add: the book uses sắc paper, is written clearly, kept in an alcove or a separate layer on the altar; large lineages copy or print several versions, one for each branch[2].
This point is worth noting: the thần chủ records only one generation, while the gia phả keeps the link between generations. When the cao tổ tablet is buried, information about that person remains in the gia phả.
Further reading
On the origins, norms, and changes of ancestor worship, see the article Thờ cúng tổ tiên của người Việt: nguồn gốc, chuẩn mực và những gì đã đổi.
