Critobulus' work, along with the writings of Doukas, Laonicus Chalcondyles and George Sphrantzes, is one of the principal sources for the Fall of Constantinople in 1453.
He changed this modern Greek family name to the more classical-sounding "Kritoboulos" in reference to a figure of that name in the dialogues of Plato.
In the 1450s he was a local political leader of the island and played an active role in the peaceful handover of Imbros, Limnos and Thasos to the Ottomans after the final breakdown of the Byzantine Empire.
In doing so, Critobulus took as a literary model the works of Flavius Josephus, the Jewish-Roman historian of the Roman destruction of Jerusalem.
His text is the most detailed historical account of the first decade of Turkish rule in Constantinople, including the Ottoman efforts of rebuilding and repopulating the city.