Byzantines were more concerned than most medieval people with the insecure business of measuring time and defining authority. In secular terms the Ottoman state already ruled far more Orthodox Christians than did the Byzantine emperor. In the fifteenth century, 'Byzantines' still called themselves 'Romans', synonymous with 'Christians'; in Greek their Church was Catholic. This chapter concentrates on the Roman Orthodox in the last century of their world. It focuses on four homelands, based on Salonica, Mistra, Constantinople and Trebizond. The city of Salonica has many names: Greek Thessalonike, Roman Thessalonica, Slav Solun, Venetian Saloniccho, Turkish Selanik and Hebrew Slonki. The history of the Morea is a late Byzantine success story, which illustrates the dilemmas faced by Roman Orthodox leaders who were caught between the west and the Ottomans. Trebizond in the Pontos, the last Byzantine Empire to be conquered by Mehemmed II, is a final illustration of the bonds which held the Roman Orthodox world together in the fifteenth century.