Responding to a 1699 report that Governor Francis Nicholson “made an order against taking up land for the importation of negroes,” John Locke wrote “well done.” The spindly marks of his quill—among the voluminous reports of imperial administration—gave me goose bumps when I first read them. I had spent several years retracing the struggle over slave law in Virginia in the decades surrounding the Glorious Revolution of 1688. That it was an imperial struggle was fascinating, even without his involvement. But the particular nature of Locke’s involvement illuminates longstanding debates about the origins of slavery in the Anglo-American empire and within democratic political systems. Efforts to find the ideological origins of slavery have long assumed that the English empire arose within a liberal context, and that America was attached to “distinctive English freedoms” from the beginning, if only for whites. In this lecture I argue that slavery developed from the same origins as the divine right of kings, and that both Locke’s Two Treatises of Government as well as his involvement in the administration of empire (on the Board of Trade) in the 1690s, show that he took steps to challenge slavery. Locke’s political theory and practical policy developed over an arc during his lifetime, such that at first both he and Shaftesbury, his mentor and the founder of the Whig party, cooperated with the Stuarts and compromised with principles of the divine right of kings and hereditary status for everyone. But Locke and others then began to sharply challenge the Stuarts, which led to the Glorious Revolution and more than a decade of legal and constitutional struggle over slavery and over rights more generally. This lecture is for those who care deeply about political theory and how it mixed with the politics of empire.