Fernández de Heredia promoted a number of translations from Latin and Greek works into Aragonese, amongst them Paulus Diaconus's Historia romana (an amplification and christianisation of Eutropius's Breviarium ab Urbe Condita), which had two translations, both promoted by Heredia. The first one was made ca. 1370-1374, from Italian into Aragonese, by Pedro de Palmerola (Historias de Roma). The second one, directly from Latin, is known as Eutropio. The codex containing the Historias de Roma translated by Palmerola, belonged to the library of the Marqués de Santillana, who ordered its translation to Alfonso Gómez de Zamora in 1439. Its contents, previously unknown, can be deduced from a copy made in 1442 by Pedro Díaz de la Torre, ordered by Ferrán Alvarez de Toledo, a cousin of don Iñigo López de Mendoza. This paper aims at analysing these translations, their transmission and their influence in Heredia's Grant crónica de Espanya.