In 1204, the Byzantine Empire was conquered by troops from western Europe ostensibly taking part in the Fourth Crusade. This was a hugely significant event for the subjects of the Empire, radically altering the Byzantines' self-image and weakening their state for the later conflict with the Ottoman Turks. Using the theory of ethnicity - a comparatively recent tool with regard to the pre-modern era - Gill Page provides fresh insight into the late Byzantine period, providing a corrective to nationalistic interpretations of the period of Frankish rule and more broadly to generally held assumptions of ethnic hostility in the period. A systematic analysis of texts in Greek from the period 1200–1420, from both ends of the social spectrum, is backed up by an in-depth study of Frankish rule in the Peloponnese to reveal the trends in the development of Byzantine identity under the impact of the Franks.