Masamune (正宗?), also known as Gorō Nyūdō Masamune (五郎入道正宗?, Priest Gorō Masamune, c.1264–1343 AD), is widely recognized as Japan's greatest swordsmith. He created swords and daggers, known in Japanese as tachi and tantō respectively, in the Soshu tradition. No exact dates are known for Masamune's life, and he has reached an almost legendary status. It is generally agreed that he made most of his swords in the late 13th and early 14th centuries, 1288–1328. Some stories list his family name as Okazaki, but some experts believe this is a fabrication to enhance the standing of the Tokugawa family.
Masamune is believed to have worked in Sagami Province during the last part of the Kamakura Period (1288–1328), and it is thought that he was trained by swordsmiths from Bizen and Yamashiro provinces, such as Saburo Kunimune, Awataguchi Kunitsuna and Shintōgo Kunimitsu. He was father by blood or adoption of Hikoshiro Sadamune, considered by many to be an almost as famous Sōshū master.
An award for swordsmiths called the Masamune prize is awarded at the Japanese Sword Making Competition. Although not awarded every year, it is presented to a swordsmith who has created an exceptional work.