This thesis uses the entirety of Margaret Cavendish's archive to present the first full account of her thought within its historical context. Living in France, the Netherlands, and England, Cavendish’s ideas were honed and in some cases prompted by her correspondences with figures who were central to the Republic of Letters, such as Constantijn Huygens, Samuel Sorbière, and Kenelm Digby. In their turn, a wide range of Cavendish’s contemporaries rigorously engaged with her publications. Bringing atomism from France to England, she encouraged Walter Charleton's translation of Pierre Gassendi's Animadversiones; Thomas Shadwell’s critique of the Royal Society in his popular satirical play, The Virtuoso, was based on The Blazing World; Arthur An...