Ahoy there me hearties! For our November treasure chest, Dr Michelle Damian gave us an excellent account of premodern piracy in Japan in three segments. The talk was designed to coincide with the major exhibition on Pirates at the National Maritime Museum in Greenwich (until late January 2026) which, although it contains nods to some Asian pirates, sadly does not include any Japanese examples. Starting with Fujiwara no Sumitomo, the 10th century ‘first recorded pirate of Japan’, Dr Damian then moved on to the Sō family who controlled the waters around the island of Tsushima, and played a key role in relations with the kings of Chǒson Korea from the 14th to 16th centuries. The third motley crew were the Murakami suigun (‘water army’, at a time when Japan still had no formally constituted navy) who operated from bases along the Inland Sea coasts, in particular from their bastions at Nōshima and Michika.
Dr Damian began with a reprise of the significance of understanding piracy in the contemporary world, citing the popular film Captain Phillips and the disruption to world shipping caused by Somali pirates. For earlier times our sources include stories, letters and evidence from archaeological evidence, which Dr Damian wove together to create compelling narratives using sophisticated geospatial analysis, generating maps that the protagonists of the tale and those pursuing them would doubtless have coveted had they been available. The differences between pirates, privateers, sea lords and maritime terrorists were laid bare, incorporated into the Japanese terms wakō 倭寇 and kaizoku海賊 which by medieval times were in effect ‘protection enterprises’, sometimes even sanctioned by the central government.
The scale of the enterprise was remarkable: Fujiwara no Sumitomo had as many as 1000 ships at his disposal from his base in Iyō on the coast of modern day Kagawa prefecture in Shikoku. An amnesty pardoned some 2500 men who were given land and food to try and deal with the problem. There was brutality, as one would expect from pirates: the same Fujiwara no Sumitomo cut the nose and ears off the Deputy Governor of Bizen province and sent them back to the Kyoto court which had dispensed the hapless official. Excavations at Dazaifu, the outpost of the central government in north Kyushu have revealed layers of burned material showing that even as important a place such as this was susceptible to pirate attacks. Treachery is another well-known feature of piracy, and Sumitomo’s hiding places were disclosed to the authorities resulting in attacks by the newly constituted navy leading to the loss of some 800 pirate ships.
The medieval period followed the loss of imperial power by the central court in Kyoto, and a period of endemic civil war, a breakdown of hereditary power structures and a shift to a more transactional economy. Many of the inhabitants of the inhospitable and rugged landscape of the island of Tsushima, between Kyushu and the Korean peninsula, turned to piracy. They were renowned seafarers, well able to take advantage of the relatively easy pickings in the heavily used shipping lanes between Kyushu and the Korean peninsula in the context of weak government in the borderlands. The power of the Sō and Soda families flourished: pirates were even given official positions in the Korean court. Dr Damian emphasised what she described as the mutable nature of borderlands, with sea battles involving pirates, Korean and Chinese Ming vessels. There were episodes of violence and blockades. Out of this emerge the sea lords, which Dr Damian depicted as ‘sensitive barbarians’, immortalised in poems describing them drinking wine with official envoys.
The dangerous waters and complicated coasts along the Inland Sea, replete with whirlpools, strong currents and challenging tidal shifts provided fertile seas for those who could turn detailed knowledge of these perils to their advantage. Dr Damian made excellent use of records describing types and volume of cargo, the names of ships captains, the amount and timing of the payment of fees and details of warehousing to argue for extensive transhipping and agreements between local captains and pirates. Bases such as Michika were clearly well-equipped (including one of, if not the oldest Korean-made cannon found in Japan, albeit apparently unused by the Murakami family), with a repertoire of material goods including sets of imported ceramics that could easily grace the home of a terrestrial lord. No matter how disruptive these pirates were, they clearly exercised a major influence over trade networks which extended to the Asian continent, and their importance was recognised by the terrestrial lords.
Many thanks to Dr Damian for a wonderful and polished presentation which brought the world of piracy in Japanese waters to life for us as we develop our new project at the Sainsbury Institute on Japan and the maritime Silk Roads.
Prof Simon Kaner
Executive Director and Head of Centre for Archaeology and Heritage