For the first time one of the grammatical texts found by the Author, composed by the Cretan humanist Zacharias Calliergis, copyist and typographer in Venice, Padua and Rome between the fifteenth and sixteenth centuries, is edited. The edition becomes an opportunity to critically resume the threads of the author's eventful biography and professional activity, which is enriched by the new aspect relating to his extraordinary skills on the complex Greek and Byzantine grammatical tradition. Among other things, the theme of the relationship between him, his typography and the famous one of Aldus Manutius in Venice is explored: the available clues lead to the conclusion that, given the profit that Manutius derived from the whole Cretan circle, culturally and philologically for the printing of his editions, probably out of opportunism he avoided waging a war of competition with them. The result is a new monograph that highlights one of the most multifaceted and interesting figures in the panorama of Greek studies that the Fall of Constantinople in Ottoman hands brought into vogue in the West.