As a student of Japanese swordsmanship, and based on what I’ve read, the sword was used rather sparingly on the battlefields of the Sengoku period in Japan, while the primary arms of the day (after about 1543) were the spear, bow, and gun. It appears that the sword assumed an entirely secondary role to the above weapons, like a back up or a side arm. My question is, if this is true, then why did so many samurai, such as Tsukahara Bokuden, Kamiizumi Hidetsuna, Yagyu Muneyoshi, etc., and their followers, dedicate their lives to the study of the sword? If the main goal of a samurai’s martial training during this period was to be able to succeed on the battlefield, then why would they spend so much of their time learning and developing techniques for a secondary battlefield weapon instead of focusing their attention on, say, the spear, since it seems to have been the principle arm in battle?

    The sword seems to have been a backup weapon for warriors through the medieval period, and became a key weapon and symbol of bushi or samurai identity only in the Tokugawa period, when samurai almost never saw
battlefields, but did carry swords around as part of their everyday dress. Researchers on the topic have agreed for a couple of decades or more that the early samurai were bowmen, and the thrust of work being done on the Nanbokucho and Sengoku periods during the past few years points very strongly to the conclusion that missile weapons (first bows, and later guns) were the primary weapon of 14th - 16th  century battlefields as well, that bladed weapons came into play only in special situations or after one side had broken ranks and begun to run, and that even then samurai preferred (and feared) spears over swords.

    The fascination of men like Bokuden or Muneyoshi with swordsmanship probably had to do with a combination of factors.

    First and foremost is probably the overlap between sword and other military skills. The idea that fighting is basically fighting, regardless of what weapon you’re using seems to have been a fundamental part of bushi military thinking from very early on. Hence warriors could use sword practice as a kind of microcosm of martial art--a vehicle to generalized expertise. In this context we need to remember that men like Bokuden were the equivalent of officers, who usually directed squads of foot soldiers from horseback. By the 15th century there seems to have been quite a bit of specialization of function in Japanese armies. The archers and gunners who appear to have been the main offensive weapons of late medieval armies were all low-ranked soldiers.

    A second factor is the effect of four centuries of post-medieval memory. We tend to forget that Bokuden, Muneyoshi, Hidetsuna, Matsumoto Bizen-no-kami and other famous late 15th and 16th  century warriors were all famous in their time as spearmen, as well as swordsmen. And most medieval bugei ryuha involved the use of numerous weapons; sword-only schools were really a product of the Tokugawa period. I suspect that much of our received image of these individuals as sword specialists is the result of selective memory born from a modern obsession with the sword.

    A third factor is the symbolic value of the sword, and its value as a personal and dueling weapon. Swords are a central part of Japanese myth and warrior ethos, appearing in the very earliest written records, and were a standard side arm of the samurai from beginning of their history. They were the weapons a warrior was most likely to be carrying, even in civilian dress. And they were both the sexiest and the most practical weapon for one-on-one duels and other off-battlefield tests of skills. Most of the great swordsmen from the Sengoku era in fact made their reputations primarily through duels and matches, not wartime, battlefield exploits.

    In other words, we remember Bokuden, Hidetsuna, Muneyoshi and the rest as swordsmen because they were most famous for their sword fights. But that doesn’t mean that they were just swordsmen--or even that they were “primarily” swordsmen. It just means that they were especially good at or especially fond of swordplay, for a variety of reasons that are only indirectly related to what they actually did on the battlefield. The situation here reminds me a little of the final scene in “Quiggly Down Under,” when Tom Selleck (whose character was famous for his expert marksmanship with a rifle) shoots down the bad guy using a handgun, and remarks “I never said I couldn’t use one, I said I don’t like ‘em.”