Supplementum Chronicarum (1483)
Composed by Giacomo Filippo Foresti in Bergamo and first printed in Venice in 1483, this "Latin Supplement to the Chronicles," as its name implies, takes the form of a supplement to a standard universal history.
The text, recorded in 15 books, concerns itself with the most significant characters of world history, from Greek mythological heroes to Old Testament prophet, and in so doing also includes material that related to the legend of Prester John.
Foresti comes to the subject of Prester John after a discussion of an otherwise unsubstantiated Ethiopian embassy to Europe that took place in the first decade of the fourteenth century. His discussion includes a reference to the lost map of Giovanni da Carignano's lost 1306 portolan chart, which has become to be understood by Prester John scholars to be the earliest text that places Prester John kingdom in Ethiopia.
Of the embassy, Foresti writes:
“Indeed, it is known that this emperor in the time of Clement V in the year of our Lord 1306 sent 30 legates to the king of the Spains; and let it be known that he was offering him aid against the infidels. They came also to Avignon to present themselves reverently to Clement V, the Pontifex Maximus, and instructed by many apostolic letters, they went to the well worth seeing places of the relics of the Apostles Peter and Paul in Rome. Having seen these, they returned with joy to their own home. But in Genoa they had to wait many days for the time to sail back, and while they waited, they had sat down [as] it happens and were asked much about their rites, customs and regions before they left, on which [this] same author has written.”
Bergamo's entry on the meeting goes as follows (qtd. in Silverberg, p. 165):
A certain priest [Carignano], the rector of St. Mark in Genoa, a truly excellent man, published a treatise, which he also called a 'map.' Among many things written in it about the state of this nation [Ethiopia] he reports that Prester John is set over that people as patriarch; and he says that under him are 127 archbishoprics, each of which has twenty bishops. Those who are to be reborn they baptize in the Roman manner, In the name of the Father and the Son and the Holy Spirit; and in the same way they celebrate the Sacrament of the Eucharist, with this one exception, that they sing the Paternoster before the elevation of the Sacrament... It is said that their emperor is most Christian, to whom seventy-four kings and almost innumerable princes pay allegiance, except those kings who observe the laws of Mahomet but submit to the emperor in other things."
Later versions contain excerpts from the Treatise on the Pontificate of Prester John, which is credited in the text to Poggio Braciolini, secretary to Pope Eugenius IV, whose source, according to Silverberg (p. 222) was Nicolò de' Conti.
Foresti mixes history and legend, treating episodes of cultural myth and Christian martyrology as historical fact. It is in this context that his account of the 1306 Ethiopian embassy to Rome should be considered.
Although once understood as the source of Giovanni da Carignano's lost account on the embassy, Verena Krebs has recently questioned the veracity not only of Foresti's account but also of the historicity of an early-fourteenth century Ethiopian embassy to Europe, citing the account's resemblance to aspects of the Prester John legend and Golden Legend along with the "socio-political entity of Solomonic Ethiopia."
