When was the first recorded account of pre-tribulation teaching? I'm not looking for Biblical support of the doctrine, but for a post-Biblical teaching that clearly articulated a pre-tribulation rapture, as opposed to a post-tribulation or mid-tribulation rapture, or clear documentation that an early Christian group specifically held pre-tribulation views.
John Darby (1800-1882), often considered the father of dispensationalism and one of the founders of the Plymouth Brethren, tends to be given credit for inventing the doctrine, or at least for having "provided the intellectual mantle that helped make it respectable." (1 2 3 4). Anti-pre-trib sources often allege that he got it from a certain Margaret MacDonald, who could be described as a proto-Pentecostal, but that's not generally seen as plausible by scholars (for instance, F.F. Bruce, who instead says that "it was in the air in the 1820s and 1830s among eager students of unfulfilled prophecy.")

C. I. Scofield (1843-1921) is also an important figure in the development of the doctrine, which popularized, legitimized, and gave authority to dispensationalism and related doctrines in the century since first publishing one of the most successful study Bibles in the world. Of course, the fact that Darby's and Scofield's eschatological schema is the default position of so many Christians owes much to writers such as Hal Lindsey (The Late Great Planet Earth) and Tim LaHaye (Left Behind) as well.

Pro-pre-trib sources would say that the seeds of the doctrine were present in the teachings of churchmen well before Darby, dating back to the first century. They may list Papias, Clement, Ignatius, Justin Martyr, Irenaeus, Tertullian, and Cyprian as supporters of the doctrine. (1 2)

However, the pre-tribulationist Larry Crutchfield says in his article, "The Blessed Hope and the Tribulation in the Apostolic Fathers":


  With few exceptions, the premillennial fathers of the early church believed that they were living in the last times.  Thus they looked daily for the Lord's return. ... It should be noted that dispensationalists have neither said that the early church was clearly pretribulational nor that there are even clear individual statements of pretribulationism in the fathers.  As Walvoord says, "the historical fact is that the early church fathers' view on prophecy did not correspond to what is advanced by pretribulationists today except for the one important point that both subscribe to the imminency of the rapture."


Crutchfield is referring to page 25 of John Walvoord's (a fellow pre-trib advocate) The Blessed Hope and the Tribulation. Just prior to that (page 24) Walvoord says:


  The preponderance of evidence seems to support the concept that the early church did not clearly hold to a rapture as preceding the end time tribulation period. Most of the early church fathers who wrote on the subject at all considered themselves already in the great tribulation. Accordingly Payne, as well as most other posttribulationists, takes the position that it is self-evident that pretribulationism as it is taught today was unheard of in the early centuries of the church. Consequently the viewpoint of the early church fathers is regarded by practically all posttribulationists, whether adherents of the classic view or not, as a major argument in favor of posttribulationism. However, the fact that most posttribulationists today do not accept the doctrine of imminency as the early church held it diminishes the force of their argument against pretribulationism.


Others list post-Reformation pre-Darby writers who wrote things that seemed to agree with the idea of a pre-tribulation rapture, but here too, it is at least clear that their idea of the rapture was not well developed. Such cited writers include John Gill and Increase Mather.

So to sum up, early church fathers taught the imminence of Christ's return, which is vital to pre-tribulation doctrine, though they believed they were in the midst of the tribulation. Many centuries later, Darby systematized the teaching of a pre-tribulation rapture, which Scofield helped rocket to popularity.