Cultivating Commons challenges the common understanding of Japanese economic and social history by uncovering diverse landholding practices in early modern Japan. In this first extended treatment of multiple systems of farmland ownership, Philip Brown argues that it was joint landownership of arable land, not virtually private landownership, that characterized a few large areas of Japan in the early modern period and even survived in some places down to the late twentieth century. The practice adapted to changing political and economic circumstances and was compatible with increasing farm involvement in the market. Brown shows that land rights were the product of villages and, to some degree, daimyo policies and not the outcome of hegemons’ and shoguns’ cadastral surveys. Joint ownership exhibited none of the “tragedy of the commons” predicted by much social science theory and in fact explicitly structured a number of practices compatible with longer-term investment in and maintenance of arable land. Exploring early modern society from the ground up, this work provides new perspectives on how villagers organized themselves and their lands, and how their practices were articulated (or were not articulated) to higher layers of administration. It employs an unusually wide array of sources and methodologies: In addition to manuscripts from local archives, it exploits interviews with modern informants who used joint ownership and a combination of modern geographical tools (hazard maps, soil maps, digital elevation models, geographic information systems technologies) to investigate the degree to which the most common form of joint ownership reflected efforts to ameliorate flood and landslide hazard risk as well as microclimate variation. Further it explores the nature of Japanese agricultural practice, its demand on natural resources, and the role of broader environmental factors—all of which infuse the study with new environmental perspectives and approaches. Cultivating Commons will be welcomed by Japanese historians, those in other regional-national fields, and social scientists concerned with issues of resource management, economic development, and rural society.