Nothing is known of Bertoldo's family. He died on 30 December 1491 at the villa of Lorenzo the Magnificent at Poggio a Caiano.[1] Bertoldo described himself as a pupil of Donatello, although there is no evidence of his having studied with that master. He worked as a sculptor in bronze, making figure groups, reliefs, and medals, and he occasionally employed other artists to cast works for him. The figure group of Bellerophon taming Pegasus,in the Kunsthistorisches Museum, Vienna, was cast by Adriano Fiorentino, and the medal for the Pazzi Conspiracy (NGA 1957.14.846.a,b and NGA 1988.30.2.a,b) was cast by Andrea Guacialoti. The other bronze figures include a statuette of Hercules on horseback, Galleria Estense, Modena; and two reliefs, of a cavalry battle and a crucifixion, in the Bargello Museum, Florence. Bertoldo is credited with the work of finishing reliefs for Donatello on the south pulpit of San Lorenzo in Florence. He also designed the terracotta frieze on the façade of the Medici villa at Poggio a Caiano and a group of twelve stucco reliefs for the Palazzo of Bartolomeo Scala in Florence.
One of his medals is signed, that of Mehmed II (NGA 1957.14.842.a,b), and there are six portrait medals and two reverse designs ascribed to him. The medals are similar in style, although some attributions are disputed.[2] All of the medals include curious faults in the composition. For example, the portrait effigies of Emperor Frederick III (NGA 1957.14.843.a,b) and Filippo de' Medici (NGA 1957.14.845.a,b) and the Pazzi Conspiracy medal are uncomfortably placed within the roundel. Several reverses include very crowded figure compositions, suggesting that the artist has misapplied the conventions that he understood from making monumental reliefs to the small scale of a medal reverse. The compositions are in themselves unrelated to the roundel format.
According to Vasari, Bertoldo was placed in charge of the Medici collection of antiquities and of the academy based upon it and so became the teacher of the young Michelangelo.
[1] Ulrich Middeldorf, "On the dilettante sculptor," Raccolta di Scritti 3 (Florence, 1981): 187-188, suggested that Bertoldo was an illegitimate son of Giovanni di Cosimo de' Medici and so a cousin of Lorenzo the Magnificent. This would explain the close familial relationship between Lorenzo and the sculptor as a member of the household. The Botticelli portrait of a young man holding a gesso medal of Cosimo il Vecchio may depict Bertoldo; see Ronald Lightbown, Sandro Botticelli, 2 vols., London, 1978: 1:38, 2:33-35, no. B22. James David Draper, "Bertolodo di Giovanni di Bertoldo," The Burlington Magazine 136, no. 1101 (December 1994): 834, has published a payment document of 1463 relating to a Bertoldo di Giovanni di Bertoldo who may be the sculptor.
[2] The attributions adopted by George Francis Hill, A Corpus of the Italian Medals of the Renaissance before Cellini, 2 vols., London, 1930: 238, were based generally on the views of Wilhelm von Bode.
[This is the artist's biography published in the NGA systematic catalogue of Renaissance medals.]