The rise in popularity of katana amongst samurai came about due to the changing nature of close-combat warfare.
The quicker draw of the sword was well suited to combat where victory depended heavily on fast response times.
The katana further facilitated this by being worn thrust through a belt-like sash (obi) with the sharpened edge facing
up. Ideally, samurai could draw the sword and strike the enemy in a single motion. Previously, the curved tachi had
been worn with the edge of the blade facing down and suspended from a belt.
The length of the katana blade varied considerably during the course of its history. In the late 14th and early 15th
centuries, katana blades tended to have lengths between 70 and 73 cm (27½ and 28½ in). During the early 16th
century, the average length approached closer to 60 cm (23½ in). By the late 16th century, the average length
returned to approximately 73 cm (28½ in).
The katana was often paired with a similar smaller companion sword, such as a wakizashi or it could also be worn
with the tanto, a smaller, similarly shaped dagger. The pairing of a katana with a smaller sword is called the daisho.
Only samurai could wear the daisho: it represented the social power and personal honor of the samurai.