Quote Originally Posted by Yora View Post
One very good reason was to be at home or taking a stroll through the village. You don't want to carry a spear or a bow with you all the time, but a sword tucked into the belt doesn't get into the way much. Given that swords were rather expensive and peasant soldiers could not afford them, you automatically got a quite reliable way to identify noble warriors by them, even when not wearing armor. From there is't a very simple step to codify it in the unspoken rule that for example a samurai must have the sword to be properly dressed and from there the written law that anyone else is forbidden from doing so.

I'm not sure if the sword became part of the dress code in Europe at any time. I have a hunch that probably Italians would have something similar, but then the major italian cities were Republics and I'm not sure there even were any nobles.

it was considered normal for a gentleman to carry a sword right up to the napoleonic era, and most modern officers still have swords for thier dress uniforms.