Something I've never understood. Why is it that Europe is the only part of the world who stuck with the double edged straight sword?
Just about every nation I've studied usually goes with a curved blade.
the Arabs also stuck to straight, double edged swords, at least until the Ottoman (or in the Levant and Egypt, Mamluk), period, when the Turks introduced them (and the Mongols solidying the trend). As you can imagine from the implication, the style was introduced to most parts of the word: it originated from China and its environs, and spread around as the people spread/invaded/migrated to the outlying regions. So the Japanese basically got their idea (in all likelyhood) for a sword from this
weapon or similar, and the Arabs got it from the Turks and Mongols.
why did it replace the straight sword? style I guess. I'm told it may be better at cutting, but how much so, I dunno, if at all.