Joko-To means swords made before the Heian period. Joko-To is not part of the sword study. The sword study starts from the Heian Period. This is considered as the archaeological field.
Jomon (縄文) period 9000 B.C.Jomon period goes back to 9000 B.C. This is the time of Paleolithic and Neolithic times. The characteristic of the time was the rope design (Jomon 縄文) on their earthenwares. We found a stone sword made during this time. They are one-piece stone swords, about 27 to 31 inches (70 to 80 cm) long, not the Neolithic type scrapers. They were made for ceremonial purposes.
Yayoi (弥生) period 300B.C —300A.D (approximately)Around 300 B.C. Yayoi culture replaced the Jomon culture. Yayoi characteristics show on their earthenwares. They are rounder, smoother, simpler design, and the techniques were greatly improved. They were named Yayoi culture because the items from this time were found in the Yayoi-Cho area (name of the place) near Tokyo University. They found bronze items such as a bronze sword (Doken 銅剣), bronze pike (Do-Hoko 銅矛), bronze mirrors (Do-Kyo 銅鏡), bronze musical instruments (Do-Taku 銅鐸). Those were imported from China and Korea but the Japanese started to make their own items later part of the Yayoi period. Iron wares were seldom excavated but we have the evidence that the iron wares existed then.
According to the Chinese history book, “Gishi wajinden” (魏志倭人伝), around 300 A.D., there was a country called Yamataikoku (邪馬台国) that controlled about 30 small countries in Japan. The head of the country was a female called Himiko (卑弥呼) who served God (shamanism). She sent a messenger to China at 239 A.D. and received a title as the head of Japan (親魏倭王), a bronze mirror, and a long sword (5 feet long). Today, we still don’t know exactly where Yamataikoku was located. This Chinese history book “Gishi wajinden” (魏志倭人伝) explains how to get to Yamataikoku, but if we follow the book’s directions exactly, we end up in the middle of the ocean, south of Kyushu (九州). We are still debating where Yamataikoku was located.
Yamato (大和) period 300 A.D. — 593 A.D
At the end of the Yayoi period, there were many small countries called Go-Zoku (豪族). Around 400 A.D., the most powerful Go-Zoku united the country and called it Yamato-Chotei (大和朝廷). This is the imperial court, the present Emperor’s ancestor. They had the power to build an enormous size tomb, called Kofun (古墳). Inside of the one of the famous kofun, Ogonzuka kofun (黄金塚古墳) in Osaka, we found swords among other things. Its hilt was made in Japan and the blade part was made in China. On the surface of the hilt, they depicted the design of a house. Also, we found many items like armor, mirror, iron tools, jewelry inside the Kofun. Outside of Kofun, they placed Haniwa (clay figurine). Those Haniwa are smiling people, animals, houses, and soldiers wearing swords. Also, they placed a tube shape haniwa (埴輪) outside of Kofun as a retaining wall. Judging from the writings on the back of mirrors and swords, they were using Kanji (Japanese characters) around 5 to 6th century.
Hilts of Japanese straight sword Kofun Period circa 600 AD. From Wikipedia Commons, the free media repository This file is licensed under the Creative Commons Attribution-Share Alike 3.0 Unported
Asuka (飛鳥) period 593 —710At the end of the Yamato period, after a long power struggle, Shotoku Taishi (聖徳太子) became a regent in 593 (beginning of the Asuka period). Shotoku Taishi established the political system and set up the first Japanese constitution (憲法17条). Shotoku Taishi protected and encouraged Buddhism and built the Horyuji temple(法隆寺) in Nara. His face had been on 10,000 yen bills for a long time. During the Asuka time, we see Kanto Tachi (環頭太刀). The shape of the hilt had a ring shape. Kan (環) means ring and To (頭) means head. Also, on the ring shape hilt, we see some inscriptions, such as the name of the Emperor, location, and numbers. The number indicates a number of years a particular emperor was enthroned. Those were all straight shape swords.
Nara (奈良) period 710 —794In 710, The capital city was moved to Nara, called Heijokyo (平城京). The shape of Joko-to was straight, usually 25 inches (60 –70 cm) long. They were suspended from the waist belt. Some swords came from China and others were made in Japan. Many swords were found from Kofun and Shoso-In(正倉院) during the Nara period. Shoso-In is a storage place where articles of Shomu Emperor (聖武天皇）were placed. Among other items, 55 swords were found from there. Those swords were called Warabite Tachi. Warabi is a name of a vegetable that grows in Japan, its stem curls up at the top. They were called Warabite- Tachi because the hilt shows the warabi shape.