I've recently been reading an ongoing letter correspondence between the Roman emperor Marcus Aurelius and his childhood teacher, Fronto.
I find it interesting that letters from both sides of this correspondence have survived, and I was wondering how it happened.
Did either Marcus or Fronto save not only the letters they received, but also made archival copies of their own letters before sending them?
Assuming that this is the case, do we assume that this collection of letters eventually passed into some official archive before being sent to a monastery library, where monks recopied them over the centuries?
It is unknown who originally published the collection of letters and how it was done, but of course much qualified speculation about it has been done by historians.
In the introduction to the Loeb edition (1955) C.R. Haines tells us that there are two likely possibilities, based on evidence that Fronto kept copies of his own letters: Either it was Fronto himself, as for example Theodor Mommsen proposed, or it was the son-in-law of Fronto and close friend of Marcus Aurelius, Aufidius Victorinus. He was heir to Fronto, and was one of the leading men during the reign of Commodus, and thus likely to have been the "literary executor" of Fronto's writings.
As can be seen it is accepted that the collection of letters was published within or shortly after the lifetime of both the correspondents, as it was referred to by a few contomperary writers. So it existed in the ancient world as a "published" book in some form closely resembling the one that is extant, although the sequence of the letters was probably different than the oldest extant manuscripts. But as can be seen it was collected long before it was copied by monks.