We find ourselves in the time right before the Hôgen Rebellion (Hôgen no ran, 保元の乱) which took place in the first year of Hôgen (1156). According to the „Hôgen-monogatari“ (保元物語), Minamoto no Tameyoshi (源為義, 1096-1156), the grandson of the famous Minamoto no Yoshiie (源義家, 1039-1106), dreamed that the eight famous armors inherited by his Seiwa-Genji line (清和源氏) of the Minamoto would be scattered to the four winds. Well, he turned out to be right in the end. Tameyoshi handed half of them secretly over to his oldest son Minamoto no Yoshitomo (源義朝, 1123-1160) and kept the remaining four. The ones he handed over were the Genta-ga-ubukinu (源太が産衣), Hizamaru (膝丸), Omodaka (沢瀉) and Hachiryô (八龍). He was now in charge of the Usukane (薄金), Tatenashi (楯無), Tsukikazu (月数) and Hikazu (日数). Tameyoshi lost his armors right in the turmoils of the Hôgen Rebellion and when Yoshitomo was defeated at the subsequent Heiji Rebellion (Heiji no ran, 平治の乱) of the first year of Heiji (1160), the armors where left back when he and others fled from Kyôto and were struggling through a snowstorm in the mountains of Mino on their way to the eastern provinces. Yoshitomo was killed while fleeing in Owari province. As usual, there exist several transmissions and theories on the whereabouts of the armors. In the following I would like to present the most common ones. I follow the order by which the armors are introduced in Ise Sadatake´s (伊勢貞丈, 1718-1784) publication „Genkô-hachiryô no yoroi-kô“ (源家八領鎧考, 1776). By the way, „Genkô-hachiryô“ (源家八領) was apart from „Genji-hachiryô“ (源氏八領) and „Genji-hakkô“ (源氏八甲) another term for these eight armors.
The Genta-ga-ubukinu (源太が産衣) was the armor worn by the eldest Minamoto son and heir at the so-called „yoroi-ki-zome“ (鎧着初), the ceremony when a 13 or 14 year-old son of a warrior family put on an armor for the first time. It is said that prince Atsuakira (敦明親王, 994-1051), the son of emperor Sanjô (三条天皇, 976-1017), presented it to his loyal retainer Minamoto no Yoriyoshi (源頼義, 988-1075) on the occasion of the birth of his son Minamoto no Yoshiie. Yoshiie´s youth name was „Genta“, thus the nickname „Genta-ga-ubukinu“ which means lit. „clothes for the newborn Genta“. The chronicles say that the armor showed the deities Amaterasu and Hachiman on the muna-ita and the left and right sode were laced to represent Wisteria blossoms. Well, it is said that at the time of the Heiji Rebellion, the Genta-ga-ubukinu was worn by the then 12 years-old Minamoto no Yoritomo (源頼朝, 1147-1199). Yoritomo was the son of Yoshitomo. The armor was lost when he had to take it off on their flight in the mountains of Mino province to be faster.
The term „usukane“ (薄金) was used to refer to a yoroi whose lamellae consisted entirely of thin metal plates. Therefore the name appears in several records what makes it a bit difficult to trace down the Usukane armor of the Minamoto. For example the „Taihei-ki“ (太平記) says it was later worn by Nitta Yoshisada (新田義貞, 1301-1338) but another transmission says that Minamoto no Yoshiie presented it to Ban Jirô Sukekane (伴次郎助兼) due to his military achievements and bravery in the Later Three-Year War (Gosannen no eki, 後三年の役) which took place in the late 1080s. Sukekane was hit by a stone-throwing ishiyumi crossbow. The helmet was destroyed but Sukekane survived and so he offered the armor of gratitude to the Sanage-jinja (猿投神社, Aichi Prefecture). An armor and the written provenance of this offering is still preserved in the shrine and the suit is designated as jûyô-bunkazai but it is doubted that it is the Usukane from the Genji-hachiryô. The extant armor is depicted below.
Picture 1: kashidori-ito-odoshi yoroi (樫鳥絲威鎧) preserved in the Sanage-jinja
As the provenance of the Sanage-jinja´s armor is doubted, we come to the one and only extant armor from the Genji-hachiryô, the Tatenashi (楯無). The nickname goes back to the saying that the armor is so robust that otherwise no (nashi, 無) shield (tate, 楯) of whatever kind is necessary. Like the Genta-ga-ubukinu, it was worn at the time of the Heiji Rebellion by Minamoto no Yoshitomo but had to be left behind in the mountains of Mino. However, this does not match with the aforementioned transmission which says that the Tatenashi stayed with Yoshitomo´s father Tameyoshi. Another transmission says that after the flight, the armor was rediscovered by Takeda Nobumitsu (武田信光, 1162-1248) who made it a heirloom of his family. But Nobumitsu was not even born when the Heiji Rebellion took place and so this transmission can be dismissed. The Takeda family in turn claims that the Tatenashi was in their possession since the time of their ancestor Minamoto no Yoshimitsu (源義光, 1045-1127), the third son of Yoriyoshi and the younger brother of Yoshiie. Takeda Shingen (武田信玄, 1521-1573) offered it later to the Kandaten-jinja (菅田天神社, Yamanashi Prefecture) but when the Takeda were destroyed, his son Katsuyori (武田勝頼, 1546-1582) ordered that it should be buried under a cedar at the grounds of the Kôgaku-ji (向嶽寺, Yamanashi Prefecture). When later Tokugawa Ieyasu occupied Kai province, he had the armor excavated and offered it once again to the Kandaten-jinja. During the Edo period the armor was damaged by a theft and some transportations and had to be repaired several times. In 1952 it was designated as kokuhô as kozakuragawa-odoshi yoroi (小桜韋威鎧). The suit is still preserved in the Kandanten-jinja and not on public display but a replica can be seen in the Yamanashi Prefectural Museum. Link to the repica.
Picture 2: kozakuragawa-odoshi yoroi preserved in the Kandanten-jinja
The Hizamaru (膝丸) has its name from the transmission that it was made of durable leather from the knees (hiza, 膝) of thousand oxen. Therefore purification rituals were required so that the spirits of the animals did not devolve upon the armor and bring bad luck. It was lost after the Heiji Rebellion.
The Hachiryô (八龍) is one of the more famous armors of the Genji-hachiryô. It has its name from the kanamono decorations in the form of the Eight Great Dragon Kings (hachi-dairyû-ô, 八大龍王). One dragon was the tatemono of the helmet, two were on the fukigaeshi, two on the kanmuri no ita of the sode, one on the munaita, one on the saidan no ita and one was on the kyûbi no ita. The „Genpei-seisui-ki“ (源平盛衰記) says that it was not lost but later eventually in the possession of Minamoto no Yoshitsune (源義経, 1159-1189) who presented it to a certain Kobayashi Jingo Muneyuki (小林神五宗行) for his military achievements during the Battle of Yashima (屋島の戦い, 1185). However, in later times the name „Hachiryô“ was used for other armors with an ornamentation of multiple dragons. The modern armorer Miura Suke´ichi (三浦助市) made in the Shôwa era a faithful reconstruction of the Hachiryô.
Picture 3: Replica of the Hachiryô by Miura Suke´ichi.
According to the „Heiji-monogatari“, the Omodaka (沢瀉) was worn during the Heiji Rebellion by Minamoto no Tomonaga (源朝長, 1143-1160), the second son of Yoshitomo. It was named after the the triangular multi-color lacing which should resemble the leaf of an omodaka (water-plantain). Such a lacing was quite common at that time and called „omodaka-odoshi“ accordingly.
The Tsukikazu (月数) was worn during the Hôgen Rebellion by Tameyoshi´s fourth son Minamoto no Yorikata (源頼賢, ?-1156). According to transmission, its lacing was of brownish (kuchiba, 朽葉) braids made of twilled silk fabric imported from China with a hemp core. Such a lacing was called „kara´aya-odoshi“ (唐綾縅) in earlier times. The name „tsukikazu“ (lit. „number of months“) goes back to the multi-colored lacing of the sode which consisted namely of twelve different colors. Another theory says that the name came either from the twelve hoshi rivets per plate of from the twelve plates the helmet bowl was made of.
And last but not least the Hikazu (日数). It was worn during the Hôgen Rebellion by Tameyoshi´´s fifth son Minamoto no Yorinaka (源頼仲, ?-1156). The transmission says that the name „hikazu“ (lit. „number of the days“) goes back to the incredibly high number of about 360 hoshi rivets on the helmet. But such an interpretation was totally uncommon during the Heian period, thus the origin of the name is doubted.