The formal subject of this book is Palm Sunday processions, with special emphasis on the presence or absence of a donkey (real, pictorial, or sculpted). All four Gospels insist that Jesus entered Jerusalem on some sort of donkey (and Harris's discussion of the terms referring to the equine and his use of scholarship on the contemporary significance of donkeys seem sound [105–107]). The author's conclusion is that Jesus intended his entry to be a repudiation of contemporary military triumphs, even as the crowd itself, by spreading cloaks and palm or other branches before him, seemed to be welcoming him as king of Israel (a fact that Harris mentions but passes over far too quickly [110]). Liturgical commemoration of the event first appears in fourth-century Jerusalem, once the city had become established as a pilgrimage site. Jerusalem's Palm Sunday liturgy remained humble, given that under Byzantine rule there was no bishop in the city, and under Muslim rule public religious displays by Christians had to be circumscribed if they were permitted at all. In any case, no reliable reports mention donkeys in these processions until the fifteenth century, when the liturgy was organized by the Franciscans who controlled the Holy Sepulchre. From Jerusalem, Palm Sunday processions spread westward, being mentioned (with little detail) in the seventh century by Isidore of Seville and the Bobbio Missal. Angilbert of Saint-Riquier's early eighth-century Institutio gives considerably more detail and shows that the procession had become an important liturgical celebration involving both monks and laity, while a little later Amalarius of Metz speaks of Palm Sunday processions with palm branches being celebrated “throughout our churches” (52). Harris devotes much attention to the Palm Sunday liturgy found in the so-called Pontifical Order of Mainz (giving the collection an authority and a firm association with Mainz that most scholars now reject), though what one might most take from his discussion is that the liturgy's development was especially spearheaded by monks (see 58–59), as it was later by Franciscans. A donkey first appears in the Life of Saint Ulrich, but only as an image (effigies) of Christ seated on an ass. Although an effigies need not be a three-dimensional representation, Harris regards it as such (146–148), holding this therefore as the first known example of a “palmesel”: a wooden sculpted figure of Christ on a donkey mounted on wheels and pulled in the procession. Palmesels quickly became fixtures in Palm Sunday processions throughout much of Europe, and still today in Latin America where they may have been introduced by Franciscans. Even more common in Latin America are pasos—sculpted figures of Christ, Mary, and saints mounted on platforms and carried in procession by tens or scores of men (and, according to Harris, women). Remarkably for a book that makes the animal so central to the author's understanding of Christian spirituality, live donkeys in Palm Sunday processions appear very rarely: besides the Jerusalem Palm Sunday procession organized by Franciscans in the fifteenth century, the only convincing instances Harris can cite have nothing to do with Palm Sunday processions at all. Rather, they appear in those English Corpus Christi plays that dramatized Christ's entry, where the donkey was ridden by a lay actor (135). Indeed, one of the more interesting facts one gleans from Harris's book is how much Palm Sunday remained (as it had been at Angilbert's Centula) one of the most important nexuses for lay participation in Catholic liturgies, since it was lay confraternities that paid for, cared for, and often paraded with palmesels and pasos.

Despite its wealth of information, Christ on a Donkey is hard to recommend. Quite apart from its jumbled exposition, entire chapters dissolve into long descriptions of palmesels and processions, interspersed with accounts of the author's own travels to view and participate in them. Harris has written less a history than a religious polemic, as in his account of the Catholic Enlightenment's opposition to palmesels, which seethes with undisguised indignation. Hence, the book's most serious problem: Harris treats every Palm Sunday procession (and often any procession at all) celebrated by kings, popes, or bishops as a “blasphemous” inversion of the message of humility of Christ's entry to Jerusalem. Charlemagne's Eastertide entry into Rome in 774 is, for Harris, truly a travesty of Christ's entry into Jerusalem, as are processions of nearly any sort by popes and bishops, monarchs and tsars. Quite apart from leading Harris to ignore the extent to which these processions descended from Roman triumphal entries (a fact he mentions only in passing, e.g., 129), his spiritual convictions cause him to misrepresent his own sources. Thus, the full text of Paride de’ Grassi's memorandum (28) actually shows how atypical Julius II's 1507 Roman entry was (while also suggesting Grassi's annoyance at being sidelined by Julius's legate in Rome). When Harris has Hrabanus Maurus criticizing Emperor Heraclius for conducting himself with un-Christlike trappings of power in entering Jerusalem, he ignores the fact that Hrabanus then has Heraclius divesting himself of those trappings to honor Christ's humility and superior kingship (14; cf. Patrologia cursus completus, series Latina, 70: 132–134 at 134). His interpretation of James Nayler's 1656 entry into Bristol as only a parody of Cromwell's entries seems contradicted by the explicit testimony of Nayler's followers that they hailed him as “the Lord of Israel” (97). And what does one do with a book which concludes with a jeremiad that includes this statement: “Consciously or not, the bombing of Lübeck [in 1942] was a stark rejection of Jesus's choice of a donkey over the military option of a chariot or a war-horse” (227)? Similar judgments appear repeatedly in Harris's book (e.g., 1, 5, 22, 26–27, 30, 46, 48, 51 . . . 213, 222 . . .). I have no quarrel with history as an expression of one's beliefs, unless the beliefs close off understanding everything save what one already understands.