(1489-1501), that of Muramasa II was Tenbun (1532–1539), and that of Muramasa III was Tenshō (1573–1591). On the other hand, Suiken Fukunaga considers the floruit of Muramasa I was around Shōchō (1428-1429) and the 1501 sword was forged by Muramasa III. Relationship to the Tokugawa dynasty Because of their exquisite sharpness, Muramasa swords were favored especially by the samurai of Mikawa (led by Tokugawa Ieyasu, the founder of the Tokugawa shogunate, and his ancestors). Naturally, when a misfortune happens in the Tokugawa clan, it is often related to Muramasa, definitely not because they are "cursed," but simply because most Mikawa samurai used these swords. Matsudaira Kiyoyasu, a grandfather of Ieyasu, was mistakenly killed by his own vassal Abe Masatoyo with a Muramasa. Ieyasu's father Matsudaira Hirotada was also stabbed with a Muramasa by Iwamatsu Hachiya, who lost his mind by excessive drinking. When Ieyasu's first son Matsudaira Nobuyasu was forced to commit suicide (seppuku), his beheader (kaishakunin) Amagata Michitsuna used a Muramasa. In spite of these unfortunate incidents, Tokugawa Ieyasu and his generation seemed to greatly appreciate Muramasa weapons. Ieyasu himself owned two swords forged by Muramasa and left them to his family; as of 2013, the Owari-Tokugawa family still holds one of the two as an heirloom. Honda Tadakatsu, one of the Four Greatest Generals under Ieyasu, wielded Tonbogiri, a legendary spear forged by Fujiwara Masazane, who studied under the Muramasa school. Sakai Tadatsugu, another of the Four, wielded Inoshishi-giri, a sword forged by Masazane. Later generations in the shogunate, however, gradually came to think of Muramasa as sinister items. Arai Hakuseki, the official scholar-bureaucrat of the shogunate, commented "Muramasa is associated with not a few sinister events." Even (1849), the official history book published from the shogunate, cites , which tells a legend that Ieyasu regarded Muramasa as cursed items and banned them from his family, 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,