Predators, Protectors, and Purveyors: Pirates and Commerce in Late Medieval Japan

Over the course of late medieval Japan (ca. 1333–1590), some leaders of seafaring bands who appear in historical sources as "pirates" (kaizoku) gained widespread acceptance as important figures in the political and economic structure of the time.¹ Japan in this period was subject to two large historical processes: decentralization in the political realm and commercialization in the economic. Contests over the post of shogun and the imperial succession, internecine inheritance feuds, and the rise of local elites resulted in a decentralized political order in which no one could fully enforce a claim to be the ultimate arbiter of sanctioned violence. In such an environment, often only brute force sufficed to resolve disputes.² At the same time, the economy was growing increasingly complex. Estate (shōen) networks linking proprietors and producers competed with, intersected with, and sometimes evolved into cash-based regional, transarchipelagic, and overseas commercial networks.³ In much of Japan, especially the Seto Inland Sea (Setonaikai ) region, commercialization occurred most dynamically in the littoral. A range of traditional and new authorities established ports, toll barriers, lodges, and other infrastructure to develop, administer, profit from, and provide support and protection for commercial enterprises.⁴

Our understanding of these processes is incomplete, however, because most historical studies have tended to focus only on the perspectives of land-based participants.⁵ The land-based economy was unquestionably central to the feeding and survival of much of the Japanese population. But to grasp comprehensively Japan's late medieval political and economic transformations, we need to embrace a worldview that recognizes waterways, not terrestrial roads, as the dominant means of bulk and long-distance transport. We need to understand the late medieval period as a window of time when the maritime world—in large part due to the efforts of seafarers who appear in the sources as pirates—asserted its autonomy and substantially impacted political and economic developments before being reabsorbed into the agricentric order of early modern Japan. Seafarers labeled as pirates in the late medieval period were in effect entrepreneurs who established control over networks of maritime production, distribution, and exchange, and who sold a variety of services, sometimes involving the use of violence, to land-based patrons. By focusing on the dominion of "pirates" as a key to understanding the late medieval economy, we can gain access to the identities of the actual carriers, protectors, and predators of maritime commerce and move towards reenvisioning Japan's late medieval commercial revolution from the waterline.

Recovering the Economic History of Pirates

Viewed globally, scholarship on pirates tends to fall along a continuum. One end is tethered by the idea that pirates were parasites who impaired the functioning of the economy.⁶ Anchoring the other end is the argument that piratical services were indispensable and inseparable from the functioning of premodern economies, whether at the level of subsistence, redistribution, or protection.⁷ Discussions of Japanese "pirates" fall along a similar continuum. Piratical violence has been one of the primary subjects of scholars arguing the case for negative impact. ⁸ Some buttress their perspectives with foundational juridical texts. Inspired by Chinese juridical models, the eighth-century ritsuryō codes outlawed pirates (kaizoku) as maritime manifestations of rebellion, robbery, and banditry;⁹ laws issued by Japan's first warrior government, the Kamakura bakufu, treated piracy as a form of illicit violence.¹⁰ Other scholars draw on Japanese, Korean, and Chinese historical sources that speak of pirates primarily as sea-based threats to the social, political, and economic order—parasites living off of the economy, sackers of ships, and extorters of taxes.¹¹ Shinjō Tsunezō has argued that some land-based authorities considered pirates to be like storms, a lurking natural disaster that might be encountered at sea.¹² The danger posed by the proliferation of pirates has been credited as one impetus for the increase in use of bills of exchange (kawase) that helped monetize the late medieval economy.¹³

Those scholars who argue for a more constructive role for pirates have tended to devote their attention to pirates' livelihoods...