Iga–Kōka alliance

The local jizamurai of Iga and Kōka were technically of peasant class yet functioned as lords,[1] and external dangers, particularly that from neighboring daimyo, threatened the social order that they had created.[2] In order to consolidate their authority, the families in Iga reached out to Kōka, immediately adjacent to the north, to form an alliance.[3] By 1487, the two confederations were jointly participating in military operations. At some point between 1552 and 1568, a constitutional document that is attributed to Iga by historians formalized the alliance. To govern the alliance, bugyō (military commissioners) from each ikki, 10 from Iga and 12 from Kōka, would gather at the border of the two regions to hold "field meetings" where they discussed strategy and other important affairs of importance to both ikki.[4] The Russian economist Vladimir V. Maltsev hypothesizes that the alliance between the provinces ended the centuries of feuding between them and thus enabled them to jointly profit from a highly lucrative mercenary market.[5]

The first documented joint operations between Iga and Kōka 1487, ninja from Iga and Kōka gained significant fame due to their actions at Magari.[6] Shogun Ashikaga Yoshihisa, concerned about the aggressive landgrabs by the Kōka shugo, Rokkaku Takayori, attacked Takayori. At Magari, Iga and Kōka ninja fought on the side of Takayori in exchange for Takayori recognizing their land ownership. The illness which prematurely killed Yoshihisa may have been at least hastened by, if not caused by wounds suffered during, the guerilla tactics and night attacks by the Iga and Kōka units.[7] The 53 ninja families in Kōka who participated in the conflict were recognized as the "Kōka 53", and 21 families were given special recognition from Takayori for their service.[7]

By the mid-1500s, the services of ninja from Iga and Kōka were in high demand, in use by at least 37 areas.[8] On December 15, 1541, the shogun in Kyoto sent a letter to Iga's governor requesting that the province assist Tsutsui Junshō in his siege of Kasagi Castle.[9] In the morning of December 23, 1541, 70–80 ninja agents from Iga and Kōka infiltrated the castle, set fire to the settlement, and were said to have captured the first and second baileys.[9] Two days later, the armies inside Kasagi sallied out and were defeated, after which the ninjas dispersed.[10]

According to the Bansenshūkai, an early Edo period document compiled in 1676 by a member of the Fujibayashi family, in 1558, Rokkaku Yoshikata was campaigning against a rebel retainer, Dodo, and besieged him in Sawayama Castle. After many days of unsuccessful siege, Yoshikata employed Tateoka Doshun from Iga to aid him. Doshun led a team of 44 Iga ninja and 4 Kōka ninja who carried lanterns Doshun had made with replicas of Dodo's mon (family crest). They entered the gates of the castle without opposition and then set fire to the castle. They escaped successfully and in the ensuing panic Yoshikata was able to capture the castle.[11] However, this account of the Rokkaku campaign against Dodo is full of errors, and accounts not derived from the Bansenshūkai do not mention ninja, let alone Tateoka Doshun, at all.[12] Dodo Oki-no-Kami Kuranosuke in actuality was a retainer of the Rokkaku's enemies, the Azai clan, and when Yoshikata invaded Northern Omi Province in 1559, Dodo was ordered by Azai Nagamasa to hold Sawayama.[13]

At an approximate date of 1560, the alliance was formalized in constitutional document.[14] Exactly how long the document was extent and how widely it applied to the villages is unknown, as is its specific provenance or date of origin.[15] It was preserved in Kōka by the Yamanaka family but was attributed to Iga by the historian Ishida Yoshihito because it refers to a "self-governing league" - sokoku ikki -, which is what Iga referred to itself as.[16] Based on references within the document, Yoshihito deduced that it was composed between 1552 and 1568.[16]

In 1568, Oda Nobunaga marched to Kyoto to install Ashikaga Yoshiaki as shogun. The Rokkaku clan in southern Ōmi Province allied with the Miyoshi clan and backed Yoshiaki's nephew and rival, Ashikaga Yoshihide, that the Miyoshi had installed in Kyoto.[17] After Rokkaku Jōtei and his sons were defeated during the invasion of Kannonji Castle, they fled first to Kōka and then Mount Kōya. From there they staged a guerrilla war against Nobunaga, assisted by the Iga and Kōka ninja forces.[18] The danger of harassment by this alliance made Nobunaga's control of southern Ōmi insecure, and in 1570 when Nobunaga retreated from the Siege of Kanegasaki back to Kyoto he was forced to go along the north-west shore of Lake Biwa rather than the more direct route through southern Ōmi.[19] Jizamurai from Iga and Kōka assisted Jōtei and his sons in raids against Nobunaga, including setting fire to the village of Heso and the southern approaches of Moriyama.[19] On July 6, 1570, these alliance forces were moving down along the Yasugawa river when an army led by Shibata Katsuie and Sakuma Morimasa, generals for Nobunaga, intercepted them at the village of Ochikubo.[19] The alliance was defeated and 780 samurai from the Iga and Kōka ikkis were killed, along with the father and son Mikumo Takanose and Mikumo Mizuhara.[20] Stephen Turnbull estimates that 780 casualties must have been enormous for Iga and Kōka, since their armies likely were not very large, and indeed Shinchō Kōki makes no reference to that alliance for the next three years.[21] Around the same time, a monk named Sugitani Zenjūbō and who is presumed to have been a mercenary ninja assassin from either Iga or Kōka, ambushed Nobunaga, fired at him, but failed to successfully assassinate him. Turnbull states that Zenjūbō fired two shots at Nobunaga, both of which were absorbed by Nobunaga's armor.[21][22] Conversely, John Man cites an interview with a local resident in Kōka City who contends that the monk was from Kōka and attempted only one shot, which missed narrowly missed Nobunaga and passed through his right sleeve.[23] He was executed three years later.[21][22]

In 1573, the shogun Yoshiaka attempted to thwart the power Nobunaga held over him and allied with the Rokkaku and the Kōka and Iga ikkis.[24] Yoshiaki began constructing a castle next to Lake Biwa. The castle was half-finished and the garrison, which included Kōka and Iga troops, was small when Nobunaga attacked. The defenders fled and begged for mercy, and Nobunaga immediately demolished the castle.[25] The same year, archers from Iga and Kōka assisted the Ikkō-ikki against Nobunaga as he retreated from the Second Siege of Nagashima.[26] Yoshiaki continued his resistance to Nobunaga but in late summer, 1573, he was defeated and forced to surrender.[27]

The alliance was terminated when Oda Nobunaga forced Kōka to surrender in 1574 after the alliance sided with Rokkaku and Ashikaga Yoshiaki against Oda. According to a document preserved by the Yamanaka family, on March 27, 1574, the remnants of the Kōka jizamurai surrendered to Nobunaga.[28] When Nobunaga invaded Iga in 1581, troops from Kōka are mentioned among Nobunaga's forces, indicating that it was now compelled to oppose its former ally.[29]

• Barducci, Polina; Orbach, Danny (2020-01-01). "Irregular Warfare in Late Medieval Japan: Towards a Historical Understanding of the "Ninja"". Journal of Military History. 84 (4): 997–1020.
• Cummins, Antony (2012). In Search of the Ninja: The Historical Truth of Ninjutsu. Cheltenham: The History Press. ISBN 9780752483559.
• Maltsev, Vladimir V. (2022-12-01). "Lessons from the Japanese ninja: on achieving a higher trade equilibrium under anarchy and private constitutions". Constitutional Political Economy. 33 (4): 433–444. doi:10.1007/s10602-021-09354-6. ISSN 1572-9966. S2CID 245276184 – via ResearchGate.
• Man, John (2012). Ninja. London: Random House. ISBN 9781446487662.
• Mie University, Faculty of Humanities, Law and Economics (2017). The Ninja Book: The New Mansenshukai. Translated by Oda, Atsuko. Tsu, Mie: Impress Corporation.{{cite book}}: CS1 maint: multiple names: authors list (link)
• Keiji, Nagahara (1988). "The medieval peasant". In Yamamura, Kozo; Hall, John Whitney (eds.). The Cambridge History of Japan. Vol. 3. Translated by Gay, Suzanne. Cambridge: Cambridge University Press. pp. 303–343. ISBN 9780521223546.
• Souyri, Pierre François (2001). The World Turned Upside Down: Medieval Japanese Society. Translated by Roth, Käthe. New York: Columbia University Press. ISBN 9780231118422.
• Souyri, Pierre F. (2010). "Autonomy and War in the Sixteenth Century Iga Region and the Birth of the Ninja Phenomena". In Ferejohn, John A.; Rosenbluth, Frances McCall (eds.). War and State Building in Medieval Japan. Stanford, California: Stanford University Press. pp. 110–123. ISBN 9780804774314.
• Turnbull, Stephen (2003). Ninja AD 1460–1650. Oxford: Osprey Publishing. ISBN 978-1-84176-525-9.
• Turnbull, Stephen (2007). Warriors of Medieval Japan. Oxford: Osprey Publishing. ISBN 978-1-84603-220-2.
• Turnbull, Stephen (2014). "The Ninja: An Invented Tradition?". Journal of Global Initiatives: Policy, Pedagogy, Perspective. 9 (1: Interdisciplinary Reflections on Japan): 9–26 – via Digital Commons.
• Turnbull, Stephen (2017). Ninja: Unmasking the Myth. Barnsley: Frontline Books. ISBN 9781473850439.