Unlike the rest of Latin Christendom, twelfth-century Outremer produced no successful candidates for canonization, although a sabbatical in the Holy Land could prove useful on a saint's curriculum vitae, such as that of the bizarre St. Ranieri of Pisa, who, while living as an ascetic in Palestine c. 1138-54, claimed to be 'God's second incarnation'.[Christopher Tyerman, God's War: A New History of the Crusades, Harvard UP (Cambridge, MA 2006) p. 219.
This is, I think, an error. Tyerman is following B. Z. Kedar here (and notes in the endnotes that this is Kedar's phrase and not, as one might think from the context, a phrase actually attributed to Ranieri by anyone). Kedar is here glossing Ranieri's hagiographer, Benincasa, and I don't think it is an accurate gloss. This is the context:
The most startling revelation takes place some time after Ranieri's miraculous Christmas transposition to Bethlehem. God tells him: 'I have made you like me; as I made myself the son of my [Jewish] people for the salvation of the human race, assuming flesh of my maid, and as I carried that flesh to heaven, so I am made now the son of my Christian people, for its salvation, by putting on your flesh. And I shall make this flesh remain on earth, to be adored by all the peoples that are on it.' What had been implied by Sidon's bishop, and the priest of the Lord's Temple, what had been alluded to in God's glosses on the Psalter at Quarantena, God proclaims now in so many words: Ranieri is nothing less than his, God's, second incarnation. Evidently Ranieri, whose first act in Jerusalem was -- as Benincasa puts it in his prologue -- to follow in his nakedness the naked Jesus, goes far beyond a mere imitation of Christ and comes to believe that he is his equal, the Father's second Son.[Benjamin Z. Kedar, "A Second Incarnation in Frankish Jerusalem," The Experience of Crusading, ii, ed. P Edbury and J. Phillips (Cambridge 2003) p. 89.]
But Kedar is surely over-reading here; it is not Ranieri but Benincasa who is portraying Ranieri's life in these terms, and therefore even if you read Benincasa as describing Ranieri as the second Incarnation, there is nothing about this suggesting that Ranieri thought so. But more than that, Benincasa is simply laying on hagiographical conventions very thickly here: the whole point of hagiography is to show the saint as someone through whom Christ can be seen, and Benincasa is an extraordinarily florid storyteller as it is. And, in any case, it doesn't make sense to read this as a claim of Incarnation; Benincasa earlier has God telling Ranieri in a vision that he was created. Rather, Benincasa is claiming that Ranieri was a dwelling-place, habitaculum, of God (to use a phrase he uses). We see this operating long before the scene Kedar relates in the above paragraph, in the Quarantena glosses, in which Ranieri, reciting the Psalter, finds God speaking through him, and then has a vision in which God tells him that all the angels and the saints will adore God in him. Kedar himself notes that Benincasa explicitly claims that people who thought he was putting himself before the Virgin, the angels, and the saints simply misunderstood him; and this should be a red flag against interpreting anything Benincasa attributes to Ranieri in a strictly literal sense. Many of the tropes are found regularly in hagiographical works; Benincasa's only remarkable feature in this regard is a lack of restraint.
But Tyerman's book is quite good; it manages to keep track of the extraordinarily complicated strands of the Crusades without getting too confusing.