De Monacis, alongside Niccolò Sagundino and Antonio Vinciguerra, published books to promote the interest of Venice and justify its territorial expansion. De Monacis drew on humanist principles to defend the foreign policy of Venice. In particular, de Monacis focused on the early history of Venice. He claimed that Venice had not been corrupted by luxury and that Venice had a divine mission of defending liberty. Marcantonio Sabellico later relied on these publications for his history of Venice.[1]
In the chronicle Chronicon de rebus Venetis ab U.C. ad annum 1354 de Monacis described the stench that the urban area of Venice emitted before a plague epidemic took hold of the city.[3] The plague reached Venice in January 1348. At the same time Venice was hit by a series of earthquakes. The city of Venice was densely populated and by March the epidemic had reached epic proportions. According to de Monacis, "squares, tombs, and all the holy places were crammed with corpses... it became necessary to take the bodies away at public expense on special ships, called pontoons, which rowed through the city, dragging the corpses from the abandoned houses." De Monacis conceded that "the plague cut down women and men, old and young in equal measures. Once it struck a house, none left alive."[4]
In 1421 de Monacis commemorated the thousand-year anniversary of founding of Venice with the treatise Oratio, dedicating it to Doge Tommaso Mocenigo.[5]
Between 1421 and 1428 de Monacis authored a laudatory account of Venice's early history under the title De gestis, moribus et nobilitate civitatis Venetiarum.[1] His narrative on the Siege of Constantinople (1204) assessed non-Venetian sources, such as the eye-witness report by Nicetas Choniates. This analysis became a main source for Historiarum ab inclinatione Romanorum imperii decades, written by the historian Flavio Biondo between 1439 and 1444.[6] The complete text of De Monaci's chronicle exists only in the very rare edition of Venice, 1758.[7] The parts on Ezzelino III da Romano were prepared for publication by Felice Osio in the early seventeenth century and published by Ludovico Antonio Muratori in Rerum Italicarum scriptores, vol. VIII.[7]
In 1425 de Monacis published an oration, to defend the war Doge Francesco Foscari waged against the Visconti of Milan. De Monacis cast Venice as defender of Christian territories against the Turks.[1]