Historians translate a variety of terms from 13th- through 17th-century Japan, China, Korea, and Europe as “Japanese pirates” (e.g., Jp. kaizoku, Kr. waegu, Ch. wokou). These constructs reflected the needs of regimes and travelers dealing with a maritime world over which they had little direct control, and often denoted bands of seafarers who based themselves in maritime regions beyond and between the reach of land-based political centers. Seafarers rarely used the terms to refer to themselves. Japanese pirates opportunistically traded, raided, and transmitted culture in periods when and places where the influence of central governments attenuated. However, some innovated forms of maritime lordship that enabled them to establish dominance over sea-lanes and territories at the heart of the Japanese archipelago. Pirates developed expertise in navigation and naval warfare that helped them acquire patrons, who provided access to networks of diplomacy and trade. In the 16th century, some Japanese pirates forged multiethnic crews that seized control of the maritime networks linking East and Southeast Asia. Labels for Japanese pirates also operated as ethnographical, geographical, and historical symbols. Traumatic assaults by waves of Japanese pirates who massacred and enslaved local populations were indelibly etched into the collective memories of Koryŏ–Chosŏn Korea and Ming–Qing China. By contrast, in early modern Japan the eradication of piracy enabled the state to extend its maritime sovereignty as well as to then commemorate pirates as ethnocentric symbols of Japanese warrior prowess.