The capture of Constantinople by the Ottoman armies of Mehmed II in 1453 was a cataclysmic event that reverberated throughout Renaissance Europe. This event intensified the exodus of Byzantines to Italy and beyond and they brought along with them the heritage of Greek antiquity. Laonikos Chalkokondyles contributed to the Renaissance with his detailed application of Herodotos to the fifteenth century, Apodeixis Historion, and made sense of the rise of the Ottomans with the lens of ancient history. The Apodeixis was printed in Latin, French, and Greek and was widely successful. The historian restored Herodotean categories of ethnicity, political rule, language, and geography to make sense of contemporary events and peoples. This was a thorough study of ancient historiography and Laonikos thus parted ways with previous Byzantine historians. I refer to Laonikos' method as "revolutionary classicizing", to describe the ways in which he abandoned the ideal of lawful imperium and restored the model of oriental tyranny when he described the nascent Ottoman state. What appears to be emulation of the ancient classics was radical revival of political concepts such as city-states as ethnic units, freedom defined as independence from foreign rule, law-giving as fundamental aspect of Hellenic tradition which did not encompass the Christian period. Laonikos has often been studied in the context of proto-nationalist historiography as he had composed a universal history, wherein he had related extensive information on various ethnic and political units in the fourteenth and fifteenth centuries. However, such proto-nationalist application does not fully capture Laonikos’ classicizing interests. Laonikos referred to his contemporaries as Hellenes, not because he was a nationalist who defined political identity only by recourse to language and common history. Rather, Laonikos believed that Hellenic identity, both referring to paganism as well as ethnicity, was relevant and not bankrupt. Importantly, we introduce manuscripts that have not yet been utilized to argue that Hellenism as paganism was living reality for Laonikos, his Platonist teacher Plethon, and their circle of intellectuals in the fifteenth century.