The traditional view that Ammianus was associated with the Roman élite (Ensslin 1922-23) and especially that he was a protégé of Symmachus and his circle (Thompson 1947) was rightly challenged by Cameron (1964).

Ammianus probably completed his Res Gestae in the early 390s. In Book 22 he mentions the great temple of Alexandria, the Serapeum, comparing its beauty with the Capitol. Had he known about the destruction of this temple by gangs of monks in the summer of 391, he would most probably have mentioned it. Yet he mentions the death of the senator Petronius Probus in 390. So his Res Gestae must have been completed between 390 and 392, since the news about the Serapeum would have reached Rome at the latest in 392. With the ending of his work our knowledge of Ammianus Marcellinus also ends.

Bibliography
- Barnes, T.D., Ammianus Marcellinus and the Representation of Historical Reality, Ithaca/London 1998
- Blockley, R.C., Ammianus Marcellinus. A Study of his Historiography and Political Thought, Brussels 1975
- Bowersock, G.W., "Review of John Matthews, The Roman Empire of Ammianus Marceli­nus", Journal of Roman Studies 80 (1990) 244-248
- Ennslin, W., "Kaiser Julian Gesetzgebungswerk und Reichsverwaltung", Klio 18 (1922-23) 104-199
- Fornara, C.W., `Studies in Ammianus Marcellinus': The letter of Libanius and Ammianus' connections with Antioch', Historia 41 (1992) 328-344
- Matthews, John, The Roman Empire of Ammianus Marcellinus, London 1989
- Matthews, John, "The Origin of Ammianus", Classical Quarterly 45 (1994) 252-269
- Thompson, E.A., The Historical Work of Ammianus Marcellinus, Cambridge 1947 (repr. Groningen 1969)