The establishment of permanent embassies in fifteenth-century Italy has traditionally been regarded as the moment of transition between medieval and modern diplomacy. In The Refugee-Diplomat, Diego Pirillo offers an alternative history of early modern diplomacy, centered not on states and their official representatives but around the figure of "the refugee-diplomat" and, more specifically, Italian religious dissidents who forged ties with English and northern European Protestants in the hope of inspiring an Italian Reformation.

Pirillo reconsiders how diplomacy worked, not only within but also outside of formal state channels, through underground networks of individuals who were able to move across confessional and linguistic borders, often adapting their own identities to the changing political conditions they encountered. Through a trove of diplomatic and mercantile letters, inquisitorial records, literary texts, marginalia, and visual material, The Refugee-Diplomat recovers the agency of religious refugees in international affairs, revealing their profound impact on the emergence of early modern diplomatic culture and practice.