These have been a tradition since the Late Middle Ages, and has displayed his own, initially that of his family, and thus not unique to himself alone, but in some cases composed by him with symbols referring to his past or his aspirations.
[1][5] Even before the early modern period, a man who did not have a family coat of arms would assume one upon becoming a bishop, as men did when knighted[6] or on achieving some other prominence.
The first depiction of a tiara, still with a single coronet, in connection with papal arms, is on the tomb of Boniface VIII (d. 1303) in the Archbasilica of Saint John Lateran.
[12] The oldest known representation of the crossed keys beneath the papal tiara in the coat of arms of the Holy See dates from the time of Pope Martin V (1417–1431).
Note that some of the images of the coats of arms shown below anachronistically include the external adornments of the papal tiara and the keys of Peter.
When a bishop and cardinal Pacelli's arms depicted a dove displayed (i.e., with its wings spread) holding an olive branch in its beak, a reference to his surname, which means "peace".
After his election to the papacy, the dove was changed to be depicted with folded wings, the rainbow was removed, and the trimount placed atop a green field above waves of water.