Most sword collectors know that the Bizen tradition was wiped out by a single large calamity towards the end of the Muromachi period. This calamity was the great flood of the Yoshii River (吉井川) which hit Bizen province on the 15th day of the eighth month Tenshô 18 (天正, 1590), at least this is what the topography „Tôbi-gunson-shi“ (東備郡村志) from Tenpô eight (天保, 1837) says which bases largely on oral transmissions from the region. Other sources mention the 19th year of Tenshô (1591) as year of the flood and the topography „Biyô-kokushi“ (備陽国志) published in the fourth year of Genbun (元文, 1739) quotes the Daiei era (大永, 1521-1528). Well, the Yoshii did burst its banks in the Daiei era but the village of Osafune was not destroyed and the then flood „just“ caused a modification in the river course. We also can say for sure that Osafune was still the sword centre of Bizen province after Daiei as numerous dated blates from later eras are extant. In short, we can narrow down the calamity to the years 1590~91. However, it is interesting that the historic sources disagree on such a major incident which happened not that long ago.
Picture 1: The left circle along the Yoshii River marks the dikes at Tennôbara. The old village of Osafune was located to the right (highlighted by the right circle). And the white dot to the north is Mt. Kumayama (508 m high).
Well, the old Osafune was actually located on a somewhat elevated place to the east of the Yoshii River. That means the village usually survived the regular floodings with only minor damages. And also a simulation with a sea level raised by 9 m (see picture 2) shows that Osafune would not have been affected that much. The reason namely for the destruction of the village was a massive landslide of Mt. Kumayama (熊山) located about 2 km to the north of Osafune. The resulting mudslide in turn broke the dikes at Tennôbara (天王原) and forced its way unstoppably towards the east destroying the villages of Osafune, Hatakeda (畠田) and Fukuoka (福岡). Since the pictures of the 2011 Tsunami we all know how devastating such a mudslide or mud-filled river can be.
Picture 2: Simulation of the sea level raised by 9 m. To the left again the dikes at Tennôbara and somewhat to the right the theoretically spared Osafune.
Let us continue with the historical records. The „Biyô-kokushi“ and the „Tôbi-gunson-shi“ say that in Osafune just one swordsmith family had survived, namely those of Yokoyama Tôshirô Sukesada (横山藤四郎祐定). But the sword publication „Kibi-tôken-kô“ (黄微刀剣考) states that there were two surviving families of smiths in Osafune and one in Hatakeda. As the mudslide took so many lives it is assumed that the landslide on Mt. Kumayama happened in the middle of the night. But we know that also the swordsmiths Jûrôzaemon Harumitsu (十郎左衛門春光) and Saemonshichirô Harumitsu (左衛門七郎春光) must had survived as there are dated blades extant from after Tenshô 19. And the meikan records also say that Tôshirô Sukesada´s younger brother Yosabei Sukesada (与三兵衛祐定) was still active after the flood. The „Biyô-kokushi“ and „Tôbi-gunson-shi“ elaborate on the incident. The former says that Tôshirô Sukesada was washed up 4 km away at the Kakiyama (蠣山) whereas the latter says that he only reached the safe shore at Nishikôzaki (西幸崎). Well, this seems rather unlikely because Nishikôzaki was located at the river mouth of the Yoshii and that means about 15 km to the south of Osafune. Local historians now assume that the last description must not be taken literally and speculate that he was washed up at the Kakiyama but found shelter at relatives in Nishikôzaki.
Again, the „Biyô-kokushi“ says that Tôshirô Sukesada, his oldest – at that time 15-years-old – son Shichibei (七兵衛), and the third and fourth son Genzaemon (源左衛門) and Sôzaemon (惣左衛門・宗左衛門) respetively had survived. According to the topography, Sukesada´s second son Gorô (五郎) drowned in the masses of water and mud. Interestingly, the meikan records do list Gorô Sukesada, namely as being active around Kan´ei (寛永, 1624-1644) and even with a 2nd generation. That means he probably had survived too. The transmissions also say that Tôshirô Sukesada took on the task of reviving the old-established Bizen forging tradition in Osafune. But we can imagine that this was not easy with just a handful of surviving families of swordsmiths. He erected his first new forge at an elevated spot about 200 to 300 m to the south of the old centre of Osafune and the next nine or ten years the smiths just tried to survive. At the time of the calamity, the lands were ruled by Ukita Hideie (宇喜多秀家, 1572-1655) who was the castellan of Okayama (岡山城). After Sekigahara all the lands of the Hideyoshi-ally were confiscated and the newly established Okayama fief (岡山藩) with the high income of 510.000 koku was entrusted to Kobayakawa Hideaki (小早川秀秋, 1582-1602). Hideaki hired Tôshirô Sukesada for a salary of 200 koku but died two years later without heir. Thereupon the Tokugawa government decided that the fief should be given nominally to the then underage Tadatsugu (池田忠継, 1599-1615), the second son of the loyal Ikeda Terumasa (池田輝政, 1565-1613). In this course, the income of the fief was newly evaluated to 280.000 koku. Terumasa was a sword lover and kept Sukesada as smith as he was one of the last who knew first-hand about the old Bizen tradition. But his son Tadatsugu died young and so the bakufu decided that Ikeda Tadakatsu (池田忠雄, 1602-1632), the then daimyô of the Sumoto fief (洲本藩) of Awaji province should be his successor. When Tadakatsu died in turn in Kan´ei nine (寛永, 1632), his oldest son and heir Mitsunaka (池田光仲, 1630-1693) was a small child and the bakufu again had to intervene in the fates of the Okayama fief. Mitsunaka had to change fiefs with his cousin Ikeda Mitsumasa (池田光政, 1609-1682), i.e. the underage Mitsunaka was now the nominal daimyô of the Tottori fief (鳥取藩) of Inaba province and Mitsumasa the new lord of Okayama. From that time onwards, the Ikeda branch of Mitsumasa ruled the Bizen-Okayama fief with an income of 315.000 koku continuously until the end of the Edo period.
In the course of these turmoils, the family of Shichibei Sukesada, Tôshirô´s son, followed the Ikeda branch which moved to Tottori in 1632. But the new daimyô Mitsumasa was also a sword lover and managed it that Sukesada was able to come back from Tottori to Osafune. Well, at that time, i.e. around Kan´ei (寛永, 1624-1644), Bizen had been outdated by the new sword centres of Ôsaka and Edo and this can be seen by the fact that Mitsumasa employed Sukesada for the peanuts of just a stipend for five persons. This was certainly not beneficial for the constant output of high-quality blades. That the situation remained bad can also be learned from extant requests of Nizaemon (仁左衛門祐定) and Shichirô´emon Sukesada (七郎右衛門祐定), the son and grandson of Tôshirô´s fourth son Sôzaemon, in which they asked for the permission to work for the Tokushima fief (徳島藩) of Awa province as they were awaiting better working conditions there. And from the rejection of the bakufu we also learn that not much was cared about the last Osafune smiths at that time. Incidentally, Nizaemon and Shichirô´emon Sukesada were active around Genroku (元禄, 1688-1704) and Genbun (元文, 1736-1741) respectively. However, Shichirô´emon´s second request from the fifth month of Shôtoku two (正徳, 1712) to become a sickle smith (kama-kaji, 鎌鍛冶) in the village of Nishikatayama (西片山) in Bizen´s Wake district (和気郡) was eventually granted.
Other smiths of the Sukesada line changed their profession and became gunsmiths or blacksmiths for farming tools, and others in turn focused on a mass-production of blades, the so-called „kazuuchi-mono“ (数打ち物), as did their Sengoku-era predecessors. That means they tried to survive by a maximum output. For example the physician and scholar Tachibana Nankei (橘南谿, 1753-1805) who was famous for his travelogues wrote later romantically about how busy Osafune was and that blades were forged in each and every corner. This picture of the somewhat later Edo period Osafune and the mass-production can be confirmed by contemporary records of the wholesaler Okamoto (岡本). Okamoto came on a regular basis from Nara to Osafune where he bought bare blades in masses and transported them home on three horses. Back in Nara he had them signed by local craftsmen according to their appearance, that means gimei of more or less famous masters were added to the tangs which matched more or less with the characteristics of the blade. These fakes were sold all over the country and soon they were pejoratively called „Nara-mono“ (奈良物).
The only Sukesada lines which were able to stand their grounds in Osafune and made it into the shinshintô era were those of Tôshirô and of his third son Genzaemon. As mentioned, the lineage of his fourth son Sôzaemon ended when the grandson of the latter became a sickle smith in 1712. Shichirô´emon Sukesada, the son of the same name of the sickle smith was merely on the paper the 4th generation of that line but his younger brother Gengorô Sukesada (源五郎祐定) had a talented son. So the later Shichirô´emon adopted his nephew as successor. This 5th generation Sukesada from the lineage of Sôzaemon entered later in Tenmei eight (天明, 1788) an apprenticeship under the Satsuma-master Yamato no Kami Motohira (大和守元平). Motohira bestowed him the character for „hira“ and he changed his name thereupon from „Sukesada“ to „Sukehira“ (祐平). Sukehira, who died in Bunsei twelve (文政, 1829) at the age of 75, is regarded with his second son Sukenaga (祐永, 1795-1851) as the driving force behind the success of the shinshintô Bizen-Yokoyama smiths. Sukehira´s first son Shichibei Sukemori (七兵衛祐盛) by the way took over the Sukesada main line of Tôshirô as 11th generation. The very last Sukesada smith was Yokoyama Gennoshin (横山元之進) who was the 8th generation of the line of Genzaemon. He died in 1930 at the age of 75.
For a better overview, I have compiled the relevant genealogies of the Sukesada lineage(s) here: