I came across mention of this old book in Paul Trebilco's history of the church in Ephesus. He noted Renan as one of the few who heavily prognasticated the eventual move of much of the first-century Jerusalem church to Ephesus. Since that was a subject of interest to me, I figured I should read it. The connection between churches was something of a disappointment; Renan sort of asserts that, but there isn't a lot of concrete evidence, as really all there is anyway are implications (otherwise, there'd be more written about this subject).
This is actually volume 4 of 7 of Renan's huge work on the early history of Christianity. This is the one that focuses most on the time period I figured would be more applicable: the destruction of the Jersusalem and the work of John in Ephesus. There's good info here, but alas, one often doesn't know where Renan pulls it from, given that there are no notes attached. Furthermore, this work is old, and it shows, insofar as Renan wrote at a time when it was considered good form to wax poetic on subjects. As such, he often takes thirty words to say what could be said in ten, which can be irritating. There are quite a few comparisons to Europeans dynamics at the time he was writing in the nineteenth century, which can be interesting but usually aren't, and while no doubt such comparisons probably were of value to his contemporaries, they didn't serve much use to this reader more than a hundred years later.
Renan's work is apparently somewhat controversial. He was a proponent of Jesus being just a man, not divine. (And Wikipedia notes various antisemetic tropes and racism in his larger work.) But surprisingly, as this volume brings out, he did mostly accept the traditional authorship of the New Testament. He was a big proponent of the idea that the Apostle John wrote Revelation—and likely the other items attributed to him. He didn't stand much for the John the Presbyter idea. All this makes for an interesting contrast, since so many modern critics espouse ideas that much of the New Testament (sometimes as little as seven letters of Paul) was written decades after its supposed authorship by pseudonymous authors. Such makes it much easier to dismiss the facts of the New Testament and make whatever claims one wishes with regard to early Christianity and Jesus. Renan doesn't do so much of that, and yet still managed to reach the conclusions he did regarding Jesus.
Much of this volume is given over to Renan's explication of Revelation, which he sees as being written in response to events in the Roman Empire, and especially with regard to Nero's persecution of Christians in Rome. Reading Revelation “historically” rather than as prophecy gives it quite a different spin.