Iron Shield

Two Iron Shields That Were Never Buried

Most ironwork from Japan's Kofun period reaches us in pieces, lifted from the soil of a burial mound after fifteen centuries underground. The two iron shields kept at Isonokami Jingu in Tenri, Nara, took a different path. They were never interred and later excavated. They were passed down above ground, kept in the shrine's sacred storehouse and handed from one generation of priests to the next. That alone sets them apart from almost everything else that survives from the same age.

Shrine tradition calls them Hi-no-mitate, the "Shields of the Sun." Each stands well over a metre tall. They are not delicate ceremonial miniatures but full-size defensive gear, made when iron armour and weapons were becoming the visible language of power in the Japanese islands.

The dating sits in the Kofun period. Most assessments place the work in the late fifth to early sixth century, while the shrine's own account leans toward the latter half of the fifth century. Both readings point to the same broad moment, a time when ironworking on the archipelago had matured enough to produce objects on this scale.

How They Were Made

Each shield was assembled from many narrow strips of iron, each around seven centimetres wide, set edge to edge and fastened with rivets into one continuous face. The result is closer to a riveted iron panel than to a cast or hammered single sheet.

The outline is worth a second look. It is not a plain rectangle. The sides draw inward at the waist and widen again toward the top and the foot, giving a gently hourglassed silhouette that the iron-workers borrowed from the wooden and leather shields of their day. The larger shield runs about 143 centimetres in length; the smaller about 139. Across the upper, middle and lower zones the width shifts noticeably, so the two faces taper and swell rather than holding a fixed breadth.

A geometric band of right-angled, interlocking lines runs across each surface. In Japanese this is the kagite-mon, a key-fret or meander design also found on certain wooden and hide shields of the period. On iron it had to be worked into the arrangement of plates and rivets rather than painted on, which is part of what makes the two pieces rewarding to compare.

Why They Are Designated

The pair was designated an Important Cultural Property on 30 May 1949, registered as archaeological material. The value rests on rarity of a particular kind. Iron corrodes, and the great majority of Kofun-period iron that we can study today came out of the ground in fragments, often badly degraded. Complete shields that were kept above ground for some fifteen hundred years are exceptional. They let researchers examine the actual construction of early Japanese defensive equipment rather than reconstruct it from rusted scraps.

Because they were never grave goods, the shields also carry an unbroken link to Isonokami Jingu itself, a sanctuary that ancient records describe as a kind of armoury for the early court. As surviving weapon material from the Kofun age, they are treated as one of the finest examples of their type in the country.

Looking Closely: A Tale of Two Shields

At a glance the shields look like twins. Spend a moment on the detail and the differences emerge. The shield held at the shrine handles the key-fret pattern with clear understanding; its work follows a regular sequence, its rivets come in two diameters, five millimetres and three, and its iron plates are about 2.4 millimetres thick.

The shield now held by the Tokyo National Museum is the looser of the two. Its key-fret is less assured, the working order less regular, the rivets a uniform five to six millimetres, and the plates around three millimetres, roughly a fifth thicker than its partner. Specialists read these signs as evidence that the museum shield was produced somewhat later than the one at the shrine.

One explanation reaches into the medieval period. The shrine's iron shields were sometimes carried out during forceful appeals and protests, and could be damaged or lost in the process. By this account, the thicker shield was made as a replacement, copying the older Kofun-period piece as its model. The proposal is offered as a hypothesis rather than settled fact, but it gives a vivid sense of how long these objects stayed in active use.

An old shrine record, the Genroku-era Isonokami Daimyojin Engi of 1699, is read by some as indicating that three shields once existed, with one since lost; the same body of tradition names the surviving pair as the Hi-no-mitate. The accounts do not align perfectly, and the safest reading is simply that two shields remain today, carrying a name and a memory older than any written tally.

The Shrine That Holds Them

Isonokami Jingu is one of the oldest shrines in Japan, named in both the Kojiki and the Nihon Shoki. Ancient tradition gives it a role beyond worship: a storehouse of weapons for the early court, its affairs looked after by the powerful Mononobe clan. For much of its history the shrine had no main sanctuary building at all. A honden was not built until 1913; before then, devotion centred on the kinsoku-chi, a sacred precinct closed to entry that lay behind the worship hall. When part of that ground was opened in 1874, swords, spearheads and beads came to light.

The grounds reward an unhurried visit. The Haiden, or hall of worship, is a National Treasure of the Kamakura period, and the worship hall of the auxiliary Izumo-Takeo shrine is likewise a National Treasure. The romon gate carries Important Cultural Property status. The same storehouse tradition that preserved the iron shields also kept the Seven-Branched Sword, the famous Nanatsusaya-no-tachi, which is a National Treasure in its own right. Flocks of sacred chickens wander the precinct freely, a small surprise for first-time visitors.

The shrine sits along the Yamanobe-no-michi, often called the oldest road in Japan, which threads past old shrines and burial mounds at the eastern edge of the Nara basin. The Furu River runs to the north, and the Yamato tumulus groups spread through the surrounding countryside, so a walk here doubles as a walk through the landscape that produced the shields in the first place.

Planning a Visit

A word of realism for anyone hoping to stand in front of the iron shields: the shrine has no treasure museum, and the shields are not on regular public view. The one held at Isonokami Jingu is kept rather than displayed, and the second is in the care of the Tokyo National Museum in Tokyo, where archaeological holdings rotate through the Japanese archaeology galleries in the Heiseikan and may be shown from time to time rather than permanently.

That should not deter the trip. The shrine precinct is freely open and rich in its own right, with two National Treasure halls, the Important Cultural Property gate and the wandering chickens. For travellers set on seeing the shields themselves, it is worth checking current exhibition schedules at the Tokyo National Museum before going, and treating the shrine visit as an encounter with the place and the tradition that carried these objects across fifteen centuries.