The codex includes: Plato’s Phaedo in the Latin translation by Leonardo Bruni d’Arezzo (ff. 1r-46v); Jerome’s Vita beati Pauli primi heremite (ff. 47r-52v); Jerome’s De monacho captivo (ff. 52v-57r); Jerome’s Vita beati Hilarionis (ff. 57r-73v); Poggio Bracciolini’s De nobilitate liber (ff. 79r-98v); Carlo Marsuppini’s De nobilitate carmen (ff. 99r-100v); Poggio Bracciolini’s Epistola ad Gregorium Corrarium (ff. 101r-103v); Eutropius’-Paul the Deacon’s Historia Romana (ff. 105r-168r). The Latin translation of Phaedo, which opens the codex, belongs to the youthful production of Leonardo Bruni d’Arezzo. It had and extraordinarily wide spread and turns out to be the first example of humanistic translating, functional to the stylistic needs of the target (Latin) language. Marco da Spilimbergo, the young notary-student who copied this text for Guarnerio, wrote another copy of Phaedo Latin translation that is nowadays the ms. 137 of the Bodmer Foundation of Cologny (doubtfully dated to 1450). The Guarnerianus codex ornamentation is made up of finely decorated initials shaping figures with soft-coloured dresses of the time on gilded foil with vegetal motives in relief, particularly on ff. 79r (a dame and a page holding a garland) and on f. 105r (a page supported by a putto holds two fishes on his arms).