Gaius Sollius Modestus Sidonius Apollinaris (c. 430 – after 489), poet, diplomat, bishop, is “the single most important surviving author from fifth-century Gaul” according to Eric Goldberg (see below). He was one of four late antiquity Gallo-Roman aristocrats whose letters survive in quantity. His letters have been compared to a literary Herculaneum, preserving under the accumulated centuries the most varied evidences of late Roman provincial life. (wikipedia and O.M. Dalton)
Bingley already briefly blogged Sidonius below, with his letters at the Early Church Fathers site. (Click on the page symbol at top and bottom to continue the letters content.)
The Fall of the Roman Empire Revisited: Sidonius Apollinaris and His Crisis of Identity Eric J. Goldberg. (Essays in History, The Corcoran Department of History at the University of Virginia).
Other than his nine books of epistulae, which contains some epigrams, he wrote the carmina, twenty-four poems (Latin text), including three panegyrics, to Anthemius, Maiorianus, and Avitus.
Sidonius Apollinaris and the Fall of Rome, AD 407-485 by Jill Harries is unfortunately out of reach pricewise for most of us.
JSTOR (limited access) has four reviews:
Author(s) of Review: William E. Klingshirn. Reviewed Work(s): Sidonius Apollinaris and the Fall of Rome, A.D. 407-485. by Jill Harries. The American Historical Review, Vol. 101, No. 3 (Jun., 1996), p. 822.
Author(s) of Review: Neil McLynn. Reviewed Work(s): Sidonius Apollinaris and the Fall of Rome, A.D. 407-485 by Jill Harries. The Journal of Roman Studies, Vol. 86 (1996), pp. 239-240.
Author(s) of Review: F. E. Romer. Reviewed Work(s): Sidonius Apollinaris and the Fall of Rome, A.D. 407-485 by Jill Harries. The American Journal of Philology, Vol. 117, No. 4 (Winter, 1996), pp. 663-666.
Author(s) of Review: Christopher Kelly. Reviewed Work(s): Sidonius Apollinaris and the Fall of Rome, AD 407-485 by J. Harries. The Classical Review, New Ser., Vol. 47, No. 1 (1997), pp. 132-134.
There is also Notes on the Carmina of Apollinaris Sidonius. W. B. Anderson. The Classical Quarterly, Vol. 28, No. 1 (Jan., 1934), pp. 17-23.
The image on top represents Saint Sidoine Apollinaire on a window in Clermont cathedral. More can be seen in this PDF file on Clermont-Ferrand.