This article examines English women who were engaged in wholesale long-distance or international trade in the later Middle Ages. These women made up only a small proportion of English merchants, averaging about 3 to 4 percent of the mercantile population, often working in partnership with their husbands. The article systematically quantifies, for the first time, women's penetration into this male-dominated trade and adds new perspectives to our understanding of women and trade in the Middle Ages by using both debt and customs records. It poses important questions about women's economic roles, the nature or distinctiveness of their businesses, and the ways that their actions fitted within mercantile activity more broadly. It examines the extent to which wives acted as equal economic partners with their husbands and also assesses the extent to which women's economic potential or agency in wholesale trade was shaped, or indeed constrained, by economic and patriarchal forces. It concludes by arguing that patriarchy certainly limited female access to wholesale markets, particularly after 1300, along with other linked features that also shaped women's economic trading endeavors. These features included status, access to capital, and the advantages to working within dynamic, extensive, and busy markets such as those found in later medieval London.