Purity Lost investigates the porous nature of social, political, and religious boundaries prevalent in the eastern Mediterranean—from the Black Sea to Egypt—during the Middle Ages. In this intriguing study, Steven A. Epstein finds that people consistently defied, overlooked, or transcended restrictions designed to preserve racial and cultural purity in order to establish relationships with those different from themselves.

These mixed relationships—among people who did not share language, creed, or skin color—undermined the pervasive claims of purity. They forced people to reflect on their own identities and the bonds—whether social, political, religious, or racial—that defined their lives. Drawing on examples from daily life and interstate politics, Epstein takes a close look at the renegades and rule-breakers of this era. He explores race, master/slave relationships, diplomatic relations between Christian Italians and Muslim Turks, religious conversions from Christian to Muslim and vice versa, and religious boundaries of the human and the angelic.

Epstein reveals the modern view of cultural, ethnic, and religious purity in the early modern Mediterranean as a mirage, and he offers new insights into how present-day conceptions about creed, color, ethnicity, and language originated.