The Kabutowari-Kanesada (甲割り兼㝎), lit. “Helmet Splitter Kanesada,” is a work of the famous late fifteenth and early sixteenth century Seki smith Izumi no Kami Kanesada (No-Sada) (和泉守兼㝎), by whom dated works from Meiō two (明応, 1493) to Daiei six (大永, 1526) exist.
The first recorded owner of the blade, Sakazaki Dewa no Kami Naomori (坂崎出羽守直盛, 1563–1616), is said to have split a man’s helmet with one hand with this sword, whereupon it was nicknamed “Helmet Splitter” accordingly. Legend has it that Naomori did it because he was so angry about not being allowed to marry Lady Sen (千姫, 1596–1666), the eldest daughter of Shōgun Tokugawa Hidetada (徳川秀忠, 1581–1621). When Naomori was about to capture Lady Sen before her upcoming second marriage, his plan was revealed and he was killed by her groom’s men, or committed seppuku as others say.
In any case, after Naomori’s death. the blade ended up in the possession of Andō Denjūrō Sadatomo (安藤伝十郎定智, 1586–1636), a retainer of Tokugawa Hidetada. For whatever reason, Sadatomi commissioned the Umetada family with shortening the blade to its current length of 52.9 cm and having his name recorded on the newly shaped tang. After Sadatomo, the blade was owned by hatamoto and tea master Taga Sakon Tsunenaga (多賀左近常長, 1592–1657).
Sakon sold the Kabutowari-Kanesada, and another wakizashi, for 200 ryō to Shōnai daimyō Sakai Tadakatsu (酒井忠勝, 1594–1647). After that, the blade remained a heirloom of the Sakai until Tadakatsu’s descendant, eleventh and next to last Sakai daimyō Tadazumi (酒井忠篤, 1853–1915), presented it to the famous “last true samurai” Saigō Takamori (西鄕隆盛, 1828–1877) when visiting Satsuma for military training at the young age of seventeen.
After Takamori’s death, the blade was passed onto Takamori’s son, Marquis Toratarō (西郷寅太郎, 1866–1919), and grandson, Marquis Kichinosuke (西郷吉之助, 1906–1977). Although a Member of the House of Lords from 1936 to 1947, a Member of the House of Counsilors from 1947 to 1971, and serving as Minister of Justice from 1968 to 1970, Saigō Kichinosuke had amassed a debt of about 400 million Yen (~ $3.6 million) by the late 1960s and had to sell most of what was left from his grandfather Takamori’s estate, incuding the Kabutowari-Kanesada and many other fine swords. The current whereabouts of the blade are, to my knowledge, unknown. As always, any input is welcome.