Among the problems of this theoretical model, one has rarely been noted (only by me, I think), which is that the term “trionfo” is used only once in the whole of the 15th century to describe the allegorical wagons themselves. The various accounts of the parades, whether actual triumphs like Alfonso’s in Naples in 1443 or Borso’s into Modena and Reggio in 1453, or several San Giovanni processions in Florence, or the occasional Magi ones, never use “trionfo” for the staged allegory itself. The only time it is so used is in a kind of off-hand remark in a letter that Galeazzo Maria Sforza wrote to his father from Ferrara on 23 July 1457, describing an elaborate scene that without his letter we would probably never have known about (maybe it is corroborated by documents in Franceschini, I haven’t checked). For the documentation see below.
I haven’t thought about it in a while, but having returned to the documents yesterday, I have a provisional theory. Briefly, the Florentine artists and merchants guilds that produced the Petrarchan cassoni and the illustrations for the earliest fully illustrated manuscripts, and also designed and produced the complex machinery for the processions (and shared the burden of producing Alfonso’s triumph), also must have conceived and designed the game of Triumphs. The conflation of the concept of “trionfo” with Petrarchan imagery and processional cars is therefore natural, although neither the game itself nor the imagery of the subjects chosen to illustrate the trumps has anything to do with Petrarch’s poem.
Galeazzo Maria’s offhand remark calling the allegories “triumphs” then implies that the term was current among youths of his class who played the game as well. He recognized the genetic resemblance of subject matter in the displays before him, and simply used the term he knew best for these sorts of allegories. Alteratively, or perhaps equally, the adults he was with used the term themselves to describe what was before them.
Galeazzo Maria Sforza visited Ferrara for a two month vacation in 1457, at the age of 13. He traveled by barge down the Po, from Pavia. Upon his arrival on 22 July, he noted twenty boats waiting to welcome him, and four of them had “triomphi” staged on them: (1) a rotating “mondo” with actors representing the four winds and astronomers; (2) a triumph of Love, with Cupid in a flaming chariot and couples in stately dance below; (3) a hill with a forest, with a fountain in the middle, with nymphs bathing, presided over by the goddess Diana; (4) a pageant of famous men of antiquity, on a rotating stage.
As far as I can discover, this is the only time in the 15th century when the term “trionfo” is used to describe these sorts of things, for which the French term “tableaux vivants” is the most common term used in the literature on this subject in English.
In her study Lebende Bilder in der italienischen Festkultur des 15. Jahrhunderts (Berlin: Akademie Verlag, 1999), Philine Helas also uses the generic term, translated into German (tableaux vivants = lebende Bilder). On pp. 3-5 of her Introduction, she discusses the variety of terms used from 15th to 17th centuries (failing to note Galeazzo Maria’s unique usage, however).
She provides Galeazzo Maria Sforza’s description as example XII on p. 195, excerpted from its first publication by Cappelli in 1894 (see below)
Here is a link to the Archivio Storico Lombardo XXI (1894) with Adriano Cappelli’s paper “Guiniforte Barzizza, Maestro di Galeazzo Maria Sforza”, relevant passage on pp. 407-408.