Cristoforo, a Mantuan, was born at an unknown date. He was probably the son of the goldsmith Geremia di Nicolino dei Geremei, mentioned in Mantuan documents from 1438 to 1480. In 1506, Raffaello Maffei da Volterra described the family as artists. The medalist's customary signature is "Christophorus Hierimae f."
Cristoforo came to Rome in 1456, and from 1461 (or possibly earlier) he was employed by Cardinal Trevisan (NGA 1957.14.806.a,b) while continuing his connection with the Mantuan court. Cristoforo visited Florence in 1462 and on the death of Trevisan in 1465 was employed by Pope Paul II. He is recorded as making jewelry for Borso d'Este in Ferrara in 1466. His papal commissions included the restoration of the statue of Marcus Aurelius, and, in 1469, he was paid for foundation medals for the re-building work at the Palazzo Venezia for Pope Paul II (NGA 1957.14.810.a,b). A number of medals of the pope are attributed to him.
Though Cristoforo's papal portrait medals are consciously modelled on the form of large bronze coins of the Roman empire, he could also handle with some breadth and style the larger cast portrait medal. An example of this is the medal of Alfonso V of Aragon, king of Naples (NGA 1957.14.804.a,b), in which the reverse reflects the Mantuan court style of Mantegna that had influenced the artist in his youth.
 Raffaele Maffei, R. Volaterrani Commentariorum Urbanum Liber, folio ccc (verso), 1506; from George Francis Hill, A Corpus of the Italian Medals of the Renaissance before Cellini, 2 vols, London, 1930: 205.
 Hill 1930, 195-201.
[This is the artist's biography published in the NGA systematic catalogue of Renaissance medals.]