>>564The main purpose of the tsuba/disc guard was to prevent your hands from sliding forward and to help your retain your grip, plus they served as ornaments, that's why historical examples have such ornamental engravings and motifs.
It all stems from basic japanese sword combat, which highly discouraged the usage of direct parries ie. blade on blade contact, because historically speaking, japanese swords were quite brittle, since they never really figured out how to make spring steel. The cutting edge of a katana was very hard, it wasn't rare that their hardness was around 60 HRC, which meant they were almost as hard as glass, but they were also as brittle as glass, so swordsmen avoided hitting hard surfaces with their weapons to avoid breakage. That's why the tsuba was more of an ornament than an actual guard, because a samurai wouldn't smash his blade directly into yours or to your guard, because it would have severly damaged it's edge or even resulted in the blade breaking apart. That's also why unlike the guard of european swords that kept evoling through the centuries to offer more and more protection, the tsuba remained relaitvely the same and the fact that they weren't main combat weapons also meant that there was no practical reason to make them more effective as actual guards. I'm not saying they were useless as guards, but the fact that japanese swordsmen themselves rarely used them to parry suggets that they weren't really seen as such.
>if these were secondary weapons, what was the primary weapon? Bows? A lance?Exactly. Most samurai were mounted archers or used spears on foot, while knights were mostly lancers and also used spears or other polearms on foot.