This dissertation uses bound labor as a lens for understanding the development of law, identity, and imperialism in the early seventeenth-century Caribbean. The Spanish, English, and French depended on bound labor, especially for their Caribbean possessions. However, the geographic proximity of their colonies and frequent warfare forced Europeans to negotiate across imperial boundaries to develop regional slave systems. At the heart of these negotiations, and the law of nations that they drew from, was the issue of reciprocity. I argue that Europeans in the Caribbean, especially the English and the French, created a transnational legal understanding that protected their ability to hold people in bondage. In order to create recognizable parameters around bound labor, Europeans referred to themselves as nations in their negotiations with one another. In other words, Europeans in the Caribbean negotiated over who could be forced into what kind of labor arrangement as nations, thereby leaving individuals seen as outside of the state, especially people of Indian and African descent, vulnerable to enslavement -- no matter their legal status as subjects of European crowns. The construction and maintenance of regional slave systems depended on the development of international law in the seventeenth-century Caribbean.