I am doing research for a screenplay I plan on writing about Justinian and Belisarius, but I'm having trouble finding information on what Belisarius's Triumph ceremony was like. The only descriptions of the Roman Triumph that I can find are about the pagan ritual, which includes painting their face red, marching their captives through the city, and sacrificing two bulls to Jupiter. I assume the ceremony was changed to accommodate Christianity, but I am having trouble finding out what was different.
Edit: I would like to sincerely thank this sub for all your help! You guys are great!
I don't have a complete answer for you because I've as yet only read a small portion of the book so far, but I will risk the wrath of the mods to recommend Mary Beard's The Roman Triumph. It is an authoritative monograph focused exclusively on the Roman ceremony. Mary Beard, as many know, is a Cambridge scholar of ancient history and has an excellent track record of high quality scholarship in her publications. I don't recall any mention of changes made to accommodate Christianity in the portion of the book that I have read, but she does discuss Belisarius' triumph in the last chapter, which I can quote from below. She states that Procopius' description of the triumph includes "all kinds of traditional triumphal features" (318), but on the other hand, she also argues that "it was significantly different from the triumphs we have been exploring" (i.e. all other before it) (319).
More specifically, Beard writes "This ceremony was taking place not in Rome, but in Constantinople, a city with its own well-established traditions of victory celebration and commemoration. It involved a procession on foot, not in a chariot, and to the Hippodrome, not to the Capitoline. And in the Christian city, no sacrifices were offered to Jupiter. Instead, both Gelimer and Belisarius prostrated themselves in front of the emperor Justinian; and the rhetoric is so far from being pagan that the moralizing slogan muttered by the king was actually a quotation from Ecclesiastes. Besides, however Procopius construes this as a triumph of Belisarius (and so a return to pre-Augustan practice), the principal honorand is more often seen as the emperor himself." (319).
She goes on for a bit more discussing the details of Procopius' account of the triumph and some of the problems in analyzing the ceremony and its history. Anyways, the book offers a comprehensive overview of what the earlier versions of the ceremony were like and some of the changes that took place over time. Hope that helps with your research.
Another source to perhaps look into is Cyril Mango's Art of the Byzantine Empire: Sources and Documents. Within a larger section on Justinian, there is a section entitled "Secular Buildings at Constantinople," featuring an excerpt written by Procopius. In it, he discusses the area around the Great Palace and Chalke Gate. The passage describes Justinian receiving "the general Belisarius, who returns to the emperor, his whole army intact, and offers him booty, namely kings and kingdoms and all other things that are prized by men. In the center stand the Emperor and Empress Theodora, both seeming to rejoice as they celebrate their victory over the kings and Vandals and the Goths, who approach them as captives of war being led into bondage. They are surrounded by the Roman Senate, one and all in festive mood . . ."
For more: Cyril Mango, "The Art of the Byzantine Empire, 312-1453: Sources and Documents" (originally Prentice Hall, 1972; Medieval Academy reprint, 2009), pp. 108-110.