But Mid-Trib (which my view vaguely qualifies as, but isn't traditional Mid-Trib as defined by Wikipedia) has to deal with a perception that clearly Pre-Trib and Post-Trib both came first and it was merely created as a compromise. (But the undeniably far younger Pre-Wrathers can't accept that argument so they focus as calling us "a Defunct view").
Pre-Tribulationism along with Dispensationalism are traditionally attributed to Darby in the early 19th Century. Though the truth is Darby was just copying and repackaging the views of Edward Irving who lived about the same time.
The attempts of Pre-Tribbers to give their view a greater antiquity include Ephraim the Syrian which claim I've already debunked. A statement in the Apocalypse of Peter which is ambiguous but at the very least is clearly predicting The Church to face Tribulation first. And attempts to read it into any reference to "Imminence" among the Church Fathers same as they do The New Testament itself.
Also Increase and Cotton Mather of the Seventeenth Century are claimed, but from what I have been able to read they seem pretty post-Trib to me, but Increase was adamant about a future Future conversion of the Jews which modern Post-Trib tends to reject.
Another name thrown out is Manuel Lacunza who died in 1801. He was a Jesuit Priest who's eschatological work was published under a false name. His book can be read online and I've seen nothing Pre-Trib in it and have seen others say outright that those labeling him Pre-Trib are lying.
However there is one claim of a Pre Irving and Darby teacher teaching a Rapture separate from the Revelation 19 event that holds up under scrutiny. And that is Morgan Edwards a Baptist preacher who lived from 1722-1795. However his timeline placed the Second Coming and Resurrection and Gathering of Believers not Seven but Three and a Half years before the start of the Millennium.
"The distance between the first and second resurrection will be somewhat more than a thousand years. I say, somewhat more—, because the dead saints will be raised, and the living changed at Christ's "appearing in the air" (I Thes. iv. 17); and this will be about three years and a half before the millennium, as we shall see hereafter: but will he and they abide in the air all that time? No: they will ascend to paradise, or to some one of those many "mansions in the father's house" (John xiv. 2), and disappear during the foresaid period of time. The design of this retreat and disappearing will be to judge the risen and changed saints; for "now the time is come that judgment must begin," and that will be "at the house of God" (I Pet. iv. 17).His model is different then my view still based on how he defined Tribulation and when he places the time of the Two Witnesses. Here is a Pre-Trib site talking about him.
So the best evidence for a Pre-Darby separate Rapture is clearly a Mid-Trib one.
The only Medieval example that can be found of a Futurist view other then Post-Trib was a cult leader trying to give a special Last Prophet status to himself. His timeline is complicated and confusing but clearly allows no more then Three and a Half years.
"Again, [Dolcino believed and preached and taught] that within those three years Dolcino himself and his followers will preach the coming of the Antichrist. And that the Antichrist was coming into this world within the bounds of the said three and a half years; and after he had come, then he [Dolcino] and his followers would be transferred into Paradise, in which are Enoch and Elijah. And in this way they will be preserved unharmed from the persecution of Antichrist. And that then Enoch and Elijah themselves would descend on the earth for the purpose of preaching [against] Antichrist. Then they would be killed by him or by his servants, and thus Antichrist would reign for a long time. But when the Antichrist is dead, Dolcino himself, who then would be the holy pope, and his preserved followers, will descend on the earth, and will preach the right faith of Christ to all, and will convert those who will be living then to the true faith of Jesus Christ."Source [Gumerlock's translation of the Latin text in Gumerlock, "A Rapture Citation," pp. 354-55.].
Mid-Trib is often accused of not popping up till the early or mid 20th Century.
But between Edwards and that point is a book predicated on claiming Louise-Napoleon III was the Antichrist (written while he was still Emperor) that predicts the Rapture to happen during the third year of the seven years, which is discussed in Chapter V (pages 77-81). So a weird view, but shows that alternatives to Pre or Post Trib were always being considered.
Going back to Pre-Darby, other 17th and 18th Century references cited are all vague, some do sound like they view the Rapture and the start of the Millennium as separate, but the exact timing is not made clear. They may not have picked a side in Pre-Trib vs Mid-Trib at all. These include Peter Jurieu, and Thomas Collier.
Peter Jurieu clearly did not teach a Secret Rapture, he refereed to it as a Glorious Apparition. Some criticisms of attempts to find early examples of Pre-Trib are discussed here. But it's unaware of Morgan Edwards.