Shape of Sword : Late Kamakura Period
What influenced the change in the shape of swords made in the late Kamakura period?(1290-1333)
The defects in Japanese swords of the time came to light after the Mongol invasions of Japan in 1274 and 1281, which facilitated a change in the battle method and shape of Japanese swords. Samurai started wearing lighter equipment which allowed them to move easily, while using long but light swords.