It was a very common name. Just kidding, kind of.
In this post at Tradition Seforim, Yitzhak of בין דין לדין reopened the did-Elijah-Levita-convert-to-Christianity-or-didn't-he issue. As I had previously posted here (and here), the great Hebrew grammarian R. Eliyah Bochur is said, in some Christian sources from the 17th and 18th centuries, to have himself eventually converted.
In my original post I assumed that this was not true, but conjectured that a confluence of circumstances contributed to the rumor. One, he had lived with a Catholic Cardinal for ten years, and had close personal associations with leading Christian Hebrew scholars. Indeed, his defense of his Jewish piety in the beginning of Massores Hamassores almost testifies that he had been thought by his fellow Jews, if not accused outright, of having converted. Secondly, he had two grandsons who converted (after his death). Thinking about it the other day, I added a third element to my conjecture, namely that his prominence and dominance in Christian scholarship needed to be explained by the Christian pious, for whom Levita was a recent teacher and authority on the Bible. Medievals like Kimhi and Aben Esdras were from the more remote past, while Levita was of the recent past. Thus, the rumor.
At the time of my original post (more than two years ago) I came across a source which stated "Elias Levita was his Grandfather by the Mother's Side, and took care of his Education. This younger Elias, who went by the Name of Joannes," but that was all that Google Books was willing to reveal at the time. This source has since become fully available for review, and here is what it says:
This excerpt, from Michel de la Roche's review of Richard Simon's Nouvelle bibliotheque choisie says it plainly: R. Elya Bachur's grandson (one of the aforementioned converts) was himself called Elias Levita. Thus, it is absolutely true that Elias Levita converted to Christianity. However, this Elias Levita was not the author of Tishby and Massores Hamassores and Methurgemann and Bovo Bukh, etc.
As for Michel de la Roche (c. 1680–1742), he "was a French Huguenot who settled in England via Holland. In 1701, he was received into the Anglican Church and naturalized as an English citizen soon after. In subsequent years, he traveled widely in Europe, sustained a long relationship with Pierre Bayle, and even translated a part of his Dictionaire into English. His primary contribution to cultural life was his literary journals produced both in French and English, serving as major conduits of scholarly information through highly informative reviews of books on the Continent for English readers and visa versa, for French readers. "
He was of the one-very-smart-guy scholarly model of the period, in which single scholars presented a great deal of learning to the public. Two-hundred-eighty years ago, you could do very well to read Michel de la Roche's Memoirs of Literature and get an idea of the contents of the major literary works of the day, and probably also to be able to pretend that you'd read them yourself.