Lady Anne Percy (1536-1591), Countess of Northumberland, was a leading figure in the Northern Rebellion of 1569, riding with the rebel forces, leading small parties of men independently, and intercepting post between Queen Elizabeth and the Regent of Scotland. After the failure of the rebellion, she became a prominent figure among the English Catholic exiles in the Low Countries throughout the 1570s. She was at the centre of a transnational network of that shared intelligence and news in support of Mary, Queen of Scots. She also became a spokesperson for the English gentlemen fugitives seeking pensions from the Spanish court, as well as backing the publication of Catholic polemical tracts. She was able to secure personal and political support from papal, Spanish, and French authorities. This edition collects Lady Anne Percy's correspondence for the first time. In a substantial introduction, Jade Scott provides an account of Lady Anne's life and her experience as an exile, first in Scotland and later on the Continent, and discusses the linguistic, rhetorical, and material features of her correspondence, highlighting the strategies that she employed to maintain her networks and ensure a position of influence throughout her life in exile.