was a medieval Japanese blacksmith widely acclaimed as Japan's greatest swordsmith. He created swords and daggers, known in Japanese as tachi and tantō, in the Sōshū school. However, many of his forged tachi were made into katana by cutting the tang (nakago) in later times ("suriage"). For this reason, his only existing works are katana, tantō, and wakizashi. No exact dates are known for Masamune's life. It is generally agreed that he made most of his swords between 1288 and 1328. Some stories list his family name as