The Journal of Korean Art and Archaeology

1. Introduction

The area of present-day Gyeongju (慶州) once served as the capital of the Silla Kingdom (新羅, 57 BCE-935), the ancient state that evolved out of Saro-guk, a member of the Jinhan confederacy. From around the fifth century CE, in the Maripgan period (fourth through early sixth century), a distinctive new type of tomb, commonly known as the “wooden-chamber tomb with stone mound” (jeokseok mokgwakbun), came into use for the ruling elite of Gyeongju. Then, from the sixth century onward, such wooden-chamber tombs with stone mounds were replaced by a new type of tomb called a “stone-chamber tomb with corridor entrance” (hoenghyeolsik seoksilbun), which was covered with an earthen mound and which could accommodate subsequent interments. The shift between these two types of tombs marks the transition from the “early” Silla burial tradition to the “late” burial tradition.

The stone-chamber tombs with corridor entrances first appeared early in the sixth century, coinciding with several major political and social changes in the Silla Kingdom. By that time, a centralized system of government had been established, Buddhism had been officially adopted and recognized as the state religion, and various state laws and decrees had been instituted. These developments mark the beginning of the period that historians refer to as the “Middle Ancient period,” or junggogi (中古期, 514-654) of Silla; accordingly, the use of stone-chamber tombs with corridor entrances is also associated with the Middle Ancient period. Used until the end of the Unified Silla period (統一新羅, 668-935), these stone-chamber tombs were also adopted by the elite of various regions outside of Gyeongju. The burial practices of the late Silla period1 are also characterized by the use of stone-lined burials into which the deceased was interred either vertically (suhyeolsik seokgwakbun) or horizontally (hoenggusik seokgwakbun); in fact, both techniques were used in the early Silla period. Cremation burials also became more popular in the late Silla period, in conjunction with the official recognition of Buddhism. Even so, the definitive element of the late Silla burial tradition is the stone-chamber tomb with corridor entrance.

Burial practices are widely viewed as manifestations of historical and social developments, and the case of Silla is no exception. As such, the burial practices prevalent during the various stages of the Silla period represent crucial evidence reflecting the sociopolitical context of the times. Therefore, this paper examines tumuli groups, tomb structure, and construction techniques of the late Silla period, with the aim of gaining insights into the social hierarchy and overall nature of the Silla Kingdom.

The late Silla burial tradition emerged around the same time that the powerful elite of the capital, or “royal city” (wanggyeong, 王京), began to actively assert direct control over local communities. As such, examining how the burial practices of the “royal city” may have influenced or structured regional burial practices in the Silla state may be a key avenue of research for considering the burials of this period. The first step in such an endeavor is to elucidate the burial tradition of the Silla center, as represented by the tumuli of the capital. Therefore, the current study focuses solely on excavated tumuli sites located in and around present-day Gyeongju.

II. Typology for Stone-chamber Tombs

1. Typological Scheme

Many structural attributes may be utilized to compare funerary architecture. In the case of stone-burial chambers with a corridor entrance, the floor plan and corridor entrance constitute the most significant attributes used for typological analysis.

Silla stone-chamber tombs with corridor entrances are generally divided into two types: those with “rectangular” chamber floors and those with “square” chamber floors. Notably, however, these types have not been clearly defined. Therefore, in order to provide objective criteria for characterizing the burial chamber types by floor plan, the floor dimensions of 202 excavated Silla stone-chamber tombs were plotted on a scattergraph (Fig. 1), where the Y-axis indicates floor length (distance between the wall with corridor entrance and opposite wall) and the X-axis indicates floor width (distance between the walls flanking the corridor entrance wall).

Fig. 1 - Scatterplot of the Dimensions of Stone-chamber Tombs.

In Figure 1, the dots clustered around the central diagonal line represent tombs with square chamber floor plans; the dots above the central diagonal line represent tombs with vertically rectangular chamber floor plans; and the dots below the central diagonal line represent tombs with horizontally rectangular chamber floor plans. Based on the data in Figure 1, a length-to-width ratio of 1:1.25 (1:0.8) represents a satisfactory means for distinguishing square and rectangular chamber floors. Therefore, in this paper, the length-to-width ratio of the floor plan will be used to classify stone-chamber tombs with corridor entrances into the following types: “vertically rectangular floor type” (AI type), with a length-to-width ratio less than 1:0.8 (i.e., wall with corridor entrance is narrower); “horizontally rectangular floor type” (AII type), which has a length-to-width ratio greater than 1:1.25 (i.e., wall with corridor entrance is wider); and “square floor type” (B type), with a length-to-width ratio in between 1:0.8 and 1:1.25.

2. Types of Stone-chamber Tombs (Figure 2)

Fig. 2 - Types of Silla Stone Chambers with Corridor Entrances.

1) Stone chamber with vertically rectangular floor (AI type): Tombs belonging to this type have a floor length-to-width ratio between 1:0.40 and 1:0.79. However, there are a limited number of tombs with floors that are more than twice as long as they are wide. This type of stone-chamber tomb has a flat ceiling consisting of two to four stone slabs. This type can be divided into the following two subtypes based on the location of the corridor entrance.

2) Stone chamber with horizontally rectangular floor (AII type): Tombs belonging to this type have a floor length-to-width ratio between 1:1.131 and 1:2.33. However, there are an extremely limited number of tombs with floors that are more than twice as wide as they are long. This type of stone-chamber tomb has a flat ceiling consisting of two to four stone slabs. This type can be divided into the following three subtypes based on the location of the corridor entrance.

3) Stone chamber with square floor (B type): Tombs belonging to this type have a floor length-to-width ratio between 1:0.82 and 1:1.24. This type of tomb has a vaulted ceiling that is capped with one or two stone slabs. This type can be divided into the following three subtypes based on the location of the corridor entrance. It should be noted that the chambers with a centrally oriented corridor tend to have floor length-to-width ratios that are closest to 1:1.

III. Chronology of Stone-chamber Tombs

A general chronology of the stone-chamber tombs with corridor entrances can be estimated based on the type of ceramic wares that were in use at the time of the tombs’ construction. The types of pottery that were being used in the period when the tombs were constructed were Late Silla-style pottery and Final Silla/Early Goryeo-style pottery. In fact, almost all of the stone-chamber tombs with corridor entrances in the Gyeongju region that have thus far been investigated coincide with the use of Late Silla-style pottery. In a previous paper, the author utilized typological analysis to establish a four-phase chronological scheme for Late Silla-style pottery. These four phases can be further divided into thirteen subphases (based on relative dating), ranging from approximately the second quarter of the sixth century to around the mideighth century. Based on this chronological scheme outlining the development of Late Silla-style pottery, a chronology for the Gyeongju stone-chamber tombs with corridor entrances can also be established, as shown in Table 1.

Stone-chamber tombs first appeared in the Gyeongju region in the early sixth century, around the time of the transition from “early” to “late” Silla pottery. Therefore, the earliest construction of stone-chamber tombs coincides with Phase 1a (“establishment” phase) of the chronology of Late Silla-style pottery, which dates to the second quarter of the sixth century. All three types of stone-chamber tombs (i.e., those with square floors, vertically rectangular floors, and horizontally rectangular floors) were in use from this time in the Gyeongju region. Notably, both stone-chamber tombs and wooden-chamber tombs with stone mounds were in use until Phase 1b, indicating that the burial traditions of both the early and late Silla period coexisted during these early phases. The use of wooden-chamber tombs with stone mounds came to an end only during Phase 1c, dating to the late sixth century, at which time the stone-chamber tombs with corridor entrances became the primary burial practice in the Silla Kingdom. The three types of stone chambers discussed above can not be used as a valid indicator of diachronic change, because all three types were in use throughout the entire period that stone-chamber tombs existed.

Notably, the number of stone-chamber tombs in the Gyeongju region seems to have dropped dramatically in Phase 3 of the chronology of Late Silla-style pottery, which dates to the second half of the seventh century. This result cannot be attributed to an unbalanced concentration of archaeological investigations on the burials of a certain period. Rather, it most likely reflects the increasing prevalence of cremation burials, which first came into use during Phase 1 in the chronology of Late Silla-style pottery. It appears that, during Phase 3, all forms of burial architecture into which the deceased was directly interred, including stone-chamber tombs with corridor entrance, significantly decreased in number.

IV. Rank of Stone-chamber Tombs and Tumuli Groups

1. Rank of Stone-chamber Tombs

As previously mentioned, the use of stone-chamber tombs with corridor entrances in the Gyeongju region began around the early sixth century, about the same time that Buddhism was officially recognized by the Silla state. Accordingly, stone-chamber tombs were not lavishly furnished with grave goods. In addition, the presence of a corridor entrance left the chambers highly susceptible to grave robbery. As such, most of the tombs have yielded only limited numbers of artifacts, making it difficult to assess the tumuli rank or the status of the deceased based solely on the artifact evidence.

Other characteristics often associated with the rank or social status of the deceased include the overall size of the stone chamber, the type of ceiling (i.e., flat or vaulted), and the construction techniques. Significantly, all three of these traits show a close correlation with the type of stone-chamber tomb, as determined by the floor plan. For example, flat ceilings typically were used for rectangular chambers, while vaulted ceilings were more commonly used for square chambers. Based on these associations, it may be possible to utilize the type and size of the burial chamber to determine the approximate social position or status of the deceased.

As seen in Fig. 3, the tombs of each type (as established in Fig. 1) tend to cluster into several groups according to the area of the burial chamber floor. These groups can then be associated with the following burial chamber “ranks,” which in turn reflect the social status of the deceased.

Fig. 3. Rank of Stone-chamber Groups.

Rank 1: Appearing in “Group a” tombs, which include

Rank 2: Appearing in “Group b1” tombs, which consist of square-chamber tombs with centrally/left/right-oriented corridor entrances (B3, B1 and B2 types, with a length of 1.90-2.60 m, width of 1.98-2.60 m, and floor area of 4.34-5.98 m²).

Rank 3: Appearing in “Group b2” tombs, which consist of square-chamber tombs with left/right-oriented corridor entrances (B1 and B2 types, with a length of 1.65-2.25 m, width of 1.70-2.20 m, and floor area of 3.06-4.14 m²).

Appearing in “Group c1” tombs, which consist of vertically rectangular-chamber tombs with left/right-oriented corridor entrances (AI1 and AI2 types, with a length of 2.10-2.50 m, width of 1.35-1.80 m, and floor area of 3.05-4.14 m²).

Appearing in “Group d1” tombs, which consist of horizontally rectangular-chamber tombs with left/right-oriented corridor entrances (AII1 and AII2 types, with a length of 1.30-1.60 m, width of 2.00-2.60 m, and floor area of 3.00-3.80 m²).

Rank 4: Appearing in “Group c2” tombs, which consist of vertically rectangular-chamber tombs with left/right-oriented corridor entrances (AI1 and AI2 types, with a length of 1.70-2.40 m, width of 0.93-1.50 m, and floor area of 1.76-2.89 m²).

Appearing in “Group d2” tombs, which consist of horizontally rectangular-chamber tombs with left/right-oriented corridor entrances (AII1 and AII2 types, with a length of 0.90-1.45 m, width of 1.25-2.20 m, and floor area of 1.85-2.90 m²).

All but one of the Rank 1 square-chamber tombs (“Group a” tombs) have centrally oriented corridor entrances, whereas the Rank 2 square chambers (“Group b1” tombs) have all three types of corridor entrances, and the Rank 3 square chambers (“Group b2” tombs) have only left- or right-oriented corridor entrances. This data suggests that hierarchical differences existed amongst the tombs with square burial chambers, in terms of both the floor area and the detailed style of the burial chamber. Meanwhile, all of the rectangular burial chambers belong to Rank 3 or below, except for the ones that are extra large in size. Based on these findings, it is possible to establish a hierarchical order for Silla stone-chamber tombs: those with square chambers and centrally oriented corridor entrances at the top, followed by those with square chambers and left/right-oriented corridor entrances, and then those with rectangular chambers at the bottom.

However, one of the “Group a” tombs has a square burial chamber and a right-oriented corridor entrance, rather than a centrally oriented one. In addition, there are three known tombs that have an extra large rectangular chamber, as represented by the dots located diagonally above and below the “Group a” cluster in Figure 3.2 Based on the pottery found within these “aberrant” Rank 1 tombs, they are thought to have been constructed during Phase 1 of the Late Silla-style pottery chronology. Although some pottery from a later date has been found in these tombs, such artifacts are believed to have been placed there during later internments. Even in such cases, the nature of the chamber structure supports the theory that these tombs were originally built around the time of Phase 1. As such, they represent the earliest known stone-chamber tombs in Gyeongju. Thus, it would seem that, during the early period, when the first stone-chamber tombs were being constructed in the Gyeongju area, the standardization or regulation of burial-chamber types according to social norms or hierarchy had not yet been established. This premise might explain the construction of aberrant types, such as the square-chamber tombs with right-oriented corridor entrance and the extra large rectangular chamber tombs.

Apart from stone-chamber tombs with corridor entrances and from cremation burials, the burial practices of the late Silla period also included stonelined burials into which the deceased was interred either vertically or horizontally. These tombs were also sparsely furnished with grave goods, making it difficult to establish distinctions based on artifact evidence alone. Following the method used for the stone-chamber tombs, the length and width of these stone-lined burials have been plotted onto the scattergraph in Figure 4, where the Y-axis represents floor length and the X-axis represents floor width. As seen in Figure 4, the dots representing stone-lined burials with vertical entrances and horizontal entrances (respectively) do not form any distinct clusters in terms of floor dimensions. This result would seem to indicate that, with the stone-lined tombs, the direction of the interment was not closely associated with the rank or status of the deceased.

Fig. 4 - Dimensions of Stone-chamber Tombs (Figure 1) and Stone-lined Burials.

All of the stone-lined burials have been classified as “Group e,” and their floor dimensions have been superimposed with those of the stone-chamber tombs in Figure 3. Based on this combined scattergraph, the “Group e” burials can first be divided into the following two clusters: “Group e1” burials, which are plotted near the Rank 3 stone-chamber tombs and thus are included with that rank, and “Group e2” burials, which are included with the Rank 4 stone-chamber tombs. However, the “Group e3” stone-lined burials are plotted below and to the left of the Rank 4 stone-chamber tombs. Since they can be clearly distinguished in terms of floor area, this group can be attributed to a separate rank, resulting in at least five different ranks for the Gyeongju-area tombs of the late Silla period. Located near the lower left corner of the scattergraph are the “Group e4” stone-lined burials, with a few small stone-chamber tombs distributed diagonally opposite them. However, given that the majority of these burials do not exceed 1.0 m in length, it is possible that they contained the remains of children.

As seen above, the burials of the late Silla period can be divided into at least five different ranks corresponding to the social position or status of the deceased. Notably, the burial tradition of the late Silla period developed during and after the Middle Ancient period, when the “bone rank” (golpum, 骨品) system of aristocratic rank was officially instituted. Based on this chronology, it seems very likely that the burial ranks were related to the Silla bone rank system. In the Samguk sagi (三國史記, Historical Record of the Three Kingdoms), one of the japji (雜志), or “miscellaneous treatise volumes,” includes a section on housing that indicates the existence of sumptuary laws at the time. Based on this reference, the Silla bone rank system may have included some restrictions regarding burial construction and use, which might explain the various ranks among the burials of the late Silla period.

The exact nature of the correlation between the Silla bone rank system and the different ranks of burials in the Gyeongju area is difficult to determine. Perhaps the simplest initial hypothesis is to associate Rank 1 burials with “true bone,” or jingol (眞骨), status, the highest level of the bone rank system. In accordance, the Rank 2 burials would correlate to the “sixth head rank,” the Rank 3 burials to the “fifth head rank,” the Rank 4 burials to the “fourth head rank,” and the Rank 5 burials to the commoners. However, even in a society where social status was determined by bloodline, as denoted by the bone rank system, there would have been individuals who were able to elevate their social status above their original blood rank, typically through military or governmental service. Therefore, the rank of the burials should not necessarily be seen to directly represent the hereditary social status of the deceased.

2. Rank of Tumuli Groups (Table 2, Figure 5)

Fig. 5 - Distribution of Late Silla Tumuli Groups.

In the Gyeongju region, tumuli groups of stone-chamber tombs exist mainly in mountainous locations surrounding the Gyeongju Basin, but some tumuli groups are also located on flatlands within the basin or on mountains at the edge of the basin. The various locations of tumuli groups comprise tombs of different ranks, a circumstance that would appear to be closely related to the initial establishment of the tumuli groups. As such, the locations of the late Silla tumuli groups likely reflect a hierarchical order.

The Seoak-dong tumuli group is situated at the foot of Mt. Seondo, west of the Gyeongju Basin, and appears to have been the highest ranked tumuli group of the late Silla burial tradition. This group consists of a row of Silla royal tombs dating to the Middle Ancient period, with large clusters of tombs on either side of the royal tombs. Thus far, excavations at this site have uncovered only a small number of Rank 1 burial chambers, but there are numerous large tombs yet to be explored in the mountain ridges that branch out from the central mountain range. This tumuli group appears to have been formed in the Middle Ancient period, when the site came to be used as the “royal cemetery” of the Silla Kingdom.

A few late Silla stone-chamber tombs with corridor entrances are also present amongst the tombs in the Noseo-dong district, which is located within the Gyeongju Basin (i.e., on flatlands). All of the stone-chamber tombs thus far excavated from this site have been found to contain Rank 1 burial chambers, which suggests that some members of the Silla royal family continued to adhere to the tradition of flatland burials, even after the establishment of the royal cemetery near Mt. Seondo in the Middle Ancient period.

The tumuli groups of the second highest rank are the Chunghyo-dong and Yonggang-dong groups, which are located in the mountains surrounding the Gyeongju Basin. These tumuli groups consist primarily of tombs with burial chambers belonging to Rank 2 and below, but a few Rank 1 chamber tombs are also present. In addition, the tombs of the Dongcheon-dong and Bomun-dong tumuli groups appear to be similar in rank to those in Chunghyo-dong and Yonggang-dong, but only a few of the Dongcheon-dong and Bomun-dong tombs have been fully excavated thus far. Notably, the tumuli groups in the mountains around the Gyeongju Basin and the Seoakdong tumuli group (examined above) represent burial grounds that were established only in the late Silla period. Therefore, these tumuli groups appear to have been established by the aristocratic elite, who previously had been buried in wooden-chamber tombs with stone mounds in the Gyeongju area, but later (from the sixth century onward) began to establish new burial grounds outside the basin.

The next rank of tumuli groups is represented by the sites of Hwangseong-dong and Bangnae-ri, as well as by the Sara-ri, Wolsan-ri, Bonggil-ri, and Gueo-ri tumuli groups. Most of these groups occur in the mountainous hinterlands outside the Gyeongju Basin, with the exception of the Hwangseong-dong group, which lies in the northern part of the Gyeongju Basin. These tumuli groups generally consist of tombs with Rank 2 burial chambers and below.3 All of these groups are either situated within or in close proximity to burial grounds that had existed since the early Silla period (or the even earlier Saro-guk period), such that they can be regarded as an extension of the earlier burial grounds. As such, this collection of tumuli groups appears to have been established in the early Silla period (or even before) by local indigenous communities that had settled in the region.

The tumuli groups at the Songok-dong and Seokjang-dong sites are characterized by tombs with Rank 3 burial chambers and below, including a high frequency of stone-lined burials with horizontal or vertical entrances. Distributed around the Gyeongju Basin, these groups appear to have been used by outlying settlements where agricultural and ceramic production took place under the control of the capital. The final rank of tumuli groups is represented by the Sinwol-ri and Yul-dong sites, which consist of only a limited number of stone-lined burials with horizontal or vertical entrances. As the stone-lined burials are generally from an early date, these burial grounds may not have been in use for a long period of time.

Based on the findings above, the tumuli groups of the late Silla burial tradition seems to demonstrate a hierarchical ordering. Furthermore, this hierarchical order may have reflected the nature of the different social groups that constructed and used these tombs.

V. Changes in Tomb Structure

1. Changes in Construction Techniques (Figure 6)

Fig. 6 - Cross-section and Plan of Silla Stone-chamber Tombs.

Most of the stone-chamber tombs with corridor entrances in the Gyeongju region were built on inclined sites in mountainous locations. The central tombs were constructed in rows along the branches of mountain ridges that extend out towards the plains, with smaller tombs located on inclined ground to the left and right of these central tombs. The first step in constructing the stone burial chambers was to dig a shallow pit to hold the foundations that would support the floor and walls. However, the majority of the main structure was located above the ground, so the stone-chamber tombs with corridor entrances can be considered an above-ground type of funerary architecture. Most of the corridor entrances of the burial chambers faced south, but the direction sometimes varied, depending upon the site’s topography.

As previously discussed, the stone-chamber tombs with corridor entrances can be divided in to various “types” based on the floor plan; those types were then subdivided into various “ranks” according to the size and other details. The overall structure of the tombs changed over time, and it would seem that the nature of these changes varied according to the rank of the burial chamber. The techniques for constructing various parts of the tombs also differed according to the rank. The burial chambers and tomb corridors were generally built from worked stone, for simple in structure, and they were built from worked stones of varying size. The flat ceilings of the rectangular burial chambers are no more than 2.0 m in height, even in the largest chambers. The vaulted ceilings of the square burial chambers are taller than the flat ceilings of the rectangular burial chambers, but their height never exceeds the length or width of the chamber. The burial platforms of this phase are low and are attached to one wall of the chamber. The corridors are short, the doorways have no frames to mark the inner entrance, and the chambers were blocked or sealed by stacking worked stones near the entrance.

Phase 2 (middle late sixth century–middle early seventh century): The Rank 1 burial chambers in this phase consist solely of square chambers with centrally orientated corridors, and their distribution was limited to the Gyeongju Basin and the surrounding mountains. The ceilings of the square chamber tombs are relatively tall, but their height does not exceed the length of any of the chamber walls. The higher ranking square burial chambers have high burial platforms that were constructed away from the chamber walls and that were plastered with lime. These platforms supported headrests, shoulder-rests, and footrests made of stone slabs. Over time, the structure of the corridor evolved and developed so that the inner entrance came to feature a lintel and a door threshold. By the end of this developmental phase, doorjambs were fitted on both sides of the inner entrance, thus completing the final form of the entrance doorframe. Initially, these corridor entrances were blocked off with a single large stone slab, but with the addition of the doorjambs, the entrance was blocked with a pair of stone slabs.

Phase 3 (late early seventh century–middle late seventh century): The square burial chambers of this phase were built using rectangular stone blocks of standardized size. These stones were stacked to form a perfect stretcher bond, with each row of stones offset by half a stone from the row above and below it. Some of the chambers have vaulted ceilings with a height that exceeds the length of the walls. The corridors became longer and the entrance was fitted with a leaf gate to allow for more convenient access.

Phase 4 (late late seventh century–middle eighth century): The corridors became longer and a “pseudo-corridor” was erected between the inner entrance and the burial chamber. With the development of the corridor structure, the burial chamber was approached first through the leaf gate to the corridor, followed by the pseudo-corridor. The burial platforms were built using stone slabs, with an additional stone slab—carved with headrest, shoulder-rest, and foot-rest—placed atop the platform.

VI. Conclusion

A hierarchy can be observed within the stone-chamber tombs with corridor entrances that formed the core of the late Silla burial tradition. These tombs, which were first constructed in the Gyeongju area in the early sixth century, had burial chambers that can be divided into several ranks that reflect the social status of the deceased. The different ranks of burial chambers were characterized by different structural features and construction methods. A hierarchy seems also to have been present amongst the late Silla tumuli groups in the Gyeongju region. The hierarchical nature of the tombs and tumuli groups of the Gyeongju region can be understood as a feature of the burial system of the Silla royal city, established during the Middle Ancient period. This burial system can shed light on the nature of the contemporaneous Silla society, which was structured by the “bone rank” system.

However, it must be stressed that the above understanding of the late Silla burial tradition should not be applied to the entire area of the Silla Kingdom. The way in which the late burial tradition of the Silla capital, including its tomb system, may have influenced the regional communities remains to be explored through further research.