In this post I begin to work through Chapter X of J.A.T. Robinson's Redating the New Testament, "A Post-Apostolic Postscript," in which he treats certain texts of the Apostolic Fathers, namely the The Epistle of Barnabas, the Shepherd of Hermas, the Didache, and 1 Clement, in that order. Not surprisingly, given his overall tendency, he dates all of these earlier than most: Barnabas to c. 75 (as opposed to the early second century), Shepherd of Hermas to c. 85 (as opposed to early to mid 2nd century), the Didache to c. 60 (as opposed to the late first or early second), 1 Clement c. 70 (as opposed to 95 or 96). In this post I begin with the Epistle of Barnabas.
Virtually all scholars agree that the Epistle of Barnabas must postdate 70, as it seems very clearly to reference the destruction of the temple, but to predate the second Jewish War of 132-135. Robinson constitutes no exception here. The primary evidence for this is 16.3-4 (here following Michael Holmes' translation): 3 "Furthermore, again he says: 'Behold, those who tore down this temple will build it themselves.' 4 This is happening now. For because they went to war, it was torn down by their enemies, and now the very servants of their enemies will rebuild it." The source for the quotation in 16.3 is unclear, although given the epistle's love of quoting Jewish scriptures and then giving a Christian interpretation thereof one suspects that it might be a now-lost Jewish text. No matter: the salient point is that this seems a pretty clear retrospective reference to the events of 70. The idea that the text must predate the second war turns upon the supposition that after 135 any lingering hope of rebuilding the temple would have been lost. Myself, I think that the post-70 limit is certain, but the pre-135 limit less compelling, as it supposes a bit too hastily judgments about who could hope for what when.
Within the 70-135 range, Robinson dates the text to Vespasian's reign (70-79). Frankly, I think that his primary reason for doing so is wafer-thin. He notes that in 4.45, Barnabas quotes Daniel 7:24 and 7:7-8 (again from Holmes): "Ten kingdoms will reign over the earth, and after them a little king will arise, who who will subdue three of the kings"; "And I saw the fourth beast, wicked and powerful and more dangerous than all the beasts of the earth, and how ten horns sprang up from it, and from these a little offshoot of a horn, and it subdued three of the large horns with single blow." Robinson argues that in Barnabas the three kings and the three large horns are taken to represent the Flavian emperors--Vespasian, Titus, and Domitian--and that the latter two already ruled alongside the first (their father) during his reign from 70 to 79. To call this interpretation speculative and the consequent chronological judgment strained would be charitable. I am really not sure what in the text would lead one to think that Barnabas intends to reference the Flavian rulers here, and even if Barnabas does it is not clear to me that one should situate them during Vespasian's rule rather than Domitian's, by which time all three would have actually been "kings." Now, properly speaking, this could involve a correction to Robinson's chronology of as little of six years, for by the end of 81 Vespasian, Titus, and Domitian had each in succession stood as emperor (Titus holding the office barely two years before his premature death caused it to pass to his brother).
That said, Robinson is probably correct in noting that the concerns addressed in Epistle of Barnabas fit a period earlier than the Hadrianic (as a date into the 120s or 130s would suppose). Indeed, and here it is I speaking and not Robinson, the letter's combination of a concern with on the one hand docetism and on the other the relationship between Christianity and Judaism seems more reminiscent of the Ignatian literature (dating to Trajan's reign, c. 98-117) than any other. Indeed, given the epistle's tendency to constantly cite "the prophets," one has to wonder if it doesn't issue from the sort of circles that Ignatius had in mind when he wrote (unsympathetically) about persons who say "If I do not find it in the archives [i.e. Old Testament], I do not believe it in the gospel" (Ignatius to the Philadelphians, 8.2, again following Holmes). My own inclination is thus to tentatively situate Barnabas in the Trajanic period, but acknowledging that these sorts of arguments are among the weaker ones for chronological reckoning. Unfortunately, given the current state of the data, I'm not sure if stronger arguments are viable.