At the time of discovery it was expected that more of the text would be found quite soon, and that further publication would be needed; but no additional pieces of the stone have come to light, and it is improbable now that they will do so in the foreseeable future. In the meantime Michel Christol has discussed the date in a paper on imperial movements in the years 256-8, and that has necessitated some modification of the commentary (Cahiers Glotz 8 (1997), 249-52, whence SEG 47.1544).
a, ll. 2-7: The names of Valerian and Gallienus can be satisfactorily restored as those in use at their accessions in A.D. 253. Gallienus' additional nomen, Egnatius, does not appear in its usual place, but it was very commonly omitted. There are also no titles of office, nor of victory. This is explained by Christol as due to excision by an editor; but since all the inscribed copies of imperial letters that I know lack the titles of office, and almost all of them the titles of victory, the omissions may relate to the category of letter - these titles being felt inappropriate to the fiction that they were man to man correspondence. Since the titles do appear in one letter of this category (Syll.3 883, Caracalla to Aurelius Julianus), I felt in 1989 that their omission could be significant, and if so possibly relevant to the date. But since they are omitted in the only other known letter of Valerian and Gallienus to an individual, I no longer believe that it is at all likely to be significant here. The absence of the younger Valerian as Caesar should also be observed, but I had already said in 1989 that he was not regularly included with his grandfather and father before 257; Christol shows that he was not in fact treated as sharing the imperial power to issue regulations unless perhaps in the very last months of his life at the end of 257 and early in 258.
l. 8. χαίρειν can be restored at the end of the line since ἔρρωσο in b, l.5, shows that the document is a letter. The recipient cannot be identified from his nomen alone, but the space available after that and before the greeting is probably too small to contain a title as well as a cognomen; he is unlikely, therefore, to have been a Roman official. Individual recipients of imperial letters are, however, all of high standing, and since it is arguable that he was not himself an Aphrodisian (see on a, ll.9, 17-18), it seems worth suggesting that he may have been a curator reipublicae. If so, his concern will have been with some aspect of the city's public finances. Problems might arise over these at any time; but in the aftermath of the creation of the new province of Caria and Phrygia (See discussion at I.2) there are likely to have been a series of them, arising from the need to reconcile old privileges with new obligations.
ll. 9-11. The space in l. 11 should indicate the end of a sentence. It is probable that its main verb partly survives in ll. 9-10, where something like οἰόμεθα may be suggested, with the subsequent infinitive in dependence; the emperors presumably indicated their view that someone (αὐτοὺσ τοὺς Ἀφροδισιεῖς) ought—or ought not—to behave in a specified way. If the Aphrodisians did appear here (and perhaps again in ll. 17-18), it seems improbable that the recipient was himself an Aphrodisian (see also on l .8), or at any rate was acting in his capacity as such.
l. 12. The conclusion of a verb in the infinitive is clear, but several words could be restored, some giving opposite meanings (e.g. βαρύνειν, λαμπρύνειν).
ll. 13-22. There is no clue here sufficient to indicate the sense; the Aphrodisians are perhaps named in ll. 17-18, and it may be that the word κοινῶν stood in ll. 18-19, possibly then carrying a reference to a common festival of a province, whether of Asia or of Caria and Phrygia.
b, l. 2. There might be a reference to a letter (ἐπιστολή) sent, perhaps, to the Aphrodisians themselves.
l. 3. The second word must be a participle (ἐηγούμενοι).
l. 4. What survives suggests that the emperors may have given the banal assurance that they would uphold civic privileges granted in the past (for a parallel cf. A & R, doc.25, ll. 11-14).
l. 6. The day and month are 23rd August. In the chancellery's file a consular date, giving the year, presumably stood at the head of the set of documents of which this was one; whether it was transferred to the copy of each document as it was sent out is not clear.
For the place from which the letter was written I have found no restoration to propose except Ἀγριππείνῃ, which I take to be Cologne—Colonia Claudia Arae Agrippinensis (Agrippinensium), whose name was naturally enough shortened in everyday use, and appears in Zonaras' account of this period as Ἀγριππίνη (Zon. 12. 24). If the restoration is accepted, the text provides the earliest known example of the usage. Ἐν with the dative to describe the place of writing is normal for imperial edicts and subscripts, but after the first century AD, emperors all seem to prefer ἀπό with the genitive for letters; ἐν here might indicate that Valerian was detached from his regular secretariat when he wrote this letter (ἀπό appears for his letter to the Philadelphians written in 255 at Antioch, SEG XXVII. 528).
It is generally agreed that Cologne was the headquarters of Gallienus in 257, and it is has recently been argued that he had already moved there in 256, but hitherto there has been no indication that Valerian ever went there after he became emperor. Correspondence concerning the eastern part of the empire, however, would surely never have been referred to Gallienus before Valerian's capture by the Parthians in 260, since Valerian was not only the senior emperor, but had taken personal command in the east. This letter, if written from Cologne, must imply a visit by Valerian to Cologne. The date of this visit is not immediately clear. In 1989 I thought that a case could be made for 254 and a better one for 256; but Christol now argues that both are excluded and 257 the only possible year. This is of course a period for which we have a very limited number of assured dates, and for the most part must be content with probabilities. It is entirely likely that Valerian went to the east soon after his accession, although he is not actually attested there before 10th January 255 (SEG 18.528), and that he was fully occupied with problems there, above all with Persian aggression, for some time. That programme could reasonably be supposed to exclude a visit to Cologne in 254 or 256. On the other hand, successes by Valerian against Parthia and by Gallienus against the Germans were celebrated at the beginning of 257 in Rome, where both emperors apparently began their joint consulates on 1st January. That both went subsequently to Cologne (where the German threat remained real) would be comprehensible. Defence works at Cologne are attributed to the period, including a gate with an inscription in which the city has the titles 'Valeriana Galliena' (CIL XIII. 8261, in which the first title is at least very probable); and their joint assumption of the title Germanicus in the same year would fit neatly into this context. This may well be the right date for the visit. Whether it is or not, the inscription suggests a rather more vigorous approach to the problems of empire than is commonly attributed to Valerian.