In the late seventeenth and early eighteenth centuries, cultural, economic, and political changes, as well as increased geographic mobility, placed strains upon British society. But by cultivating friendships and alliances, women worked to socially cohere Britain and its colonies. In the first book-length historical study of female friendship and alliance for the early modern period, Amanda Herbert draws on a series of interlocking microhistorical studies to demonstrate the vitality and importance of bonds formed between British women in the long eighteenth century. She shows that while these alliances were central to womens lives, they were also instrumental in building the British Atlantic world.