Origin The exact origin of the Muramasa school is unknown. The oldest extant sword equipped with both a name sign Muramasa and a date sign shows the year
Bunki 1 (1501). Scholars, however, assert several swords signed with Muramasa (but without year signs) are slightly older than 1501 in light of their styles. Another theory states that Muramasa was a student of Heianjō Nagayoshi, a prominent
Kyoto swordsmith known for spears and engravings. The school of , a notable branch of the Muramasa school, records Masashige died in 1456, so Muramasa was active before 1456 if we believe the record. Another popular legend says the mother of Muramasa worshipped the
bodhisattva Senju Kannon and thus he was called Sengo, a shortened form of .
Matsudaira Kiyoyasu, a grandfather of Ieyasu, was mistakenly killed by his own vassal Abe Masatoyo with a Muramasa. although it is clearly a fabricated story considering the heirloom of the Owari-Tokugawa family. In the
Bakumatsu period (1853–1868), Muramasa was somehow considered to be a curse bringer against the shogunate, and thus
shishi (anti-Tokugawa activists) wished to acquire Muramasa blades. Even though the school of Muramasa does not have an exalted or prestigious status to be used by the imperial family in ordinary times, a Muramasa was wielded by
Prince Arisugawa Taruhito, the commander-in-chief of the Imperial Army against the Tokugawa shogunate during the
Boshin War (1868–1869). To satisfy growing demand, forgeries of Muramasa blades were also often made in this period. == Cultural significance ==