As a son of the Emperor Avitus, Ecdicius was educated at Augustonemetum (modern Clermont-Ferrand), where he lived and owned some land. In the 460s he was one of the richest and most important persons in the western Empire and he was present at the court of Anthemius until 469.
Ecdicius and his brother-in-law Sidonius Apollinaris, the Bishop of Clermont, took charge of the defence of the Auvergne against the Visigoths from 471 to 474. The Visigothic king Euric besieged many cities, but Ecdicius, with a private army of horsemen paid for out of his own wealth, brought provisions to those cities, lifted their sieges, and fed a multitude of poor. The size of his warband seems to have been quite small --- he broke a Visigothic siege of Clermont-Ferrand with only eighteen horsemen, or ten according to the non-contemporary account of Gregory of Tours.
In 471 Anthemius sent an army into Gaul under the command of his son Anthemiolus against the Visigoths, but he was defeated near Arles; by 473 the Visigoths had captured Arles and Marseille, and they appeared poised for an invasion of Italia itself. Ecdicius was elevated to the rank of patrician by the new emperor Julius Nepos, and invested with the title magister militum praesentialis, apparently with the intent to wage war against the Visigoths; when Sidonius learned of this promotion, he shared his hopes with his wife Papianilla that Ecdicius might gain victories and be rewarded with the Consulate.
However, just as Ecdicius embarked on his campaign against the Visigoths (475), he was recalled to Italy by Julius and Flavius Orestes replaced him as head of the Roman army. The emperor then exchanged the Auvergne for Provence, giving the Visigoths the territories they had long desired. The reason for Nepos's about face is puzzling, as Ralph W. Mathisen admits before accusing the Senate in Rome of being responsible.
After he was replaced, Ecdicius practically vanishes from the historical record. A letter written by Sidonius Apollinaris survives, in which he pleads with his brother-in-law to return to the Auvergne; but if Ecdicius did return – or even if Sidonius sent the letter – is unknown. Some evidence suggests that he remained in Italy: there is a letter in the Variae of Cassiodorus (2.4.22), written after the Battle of Vouillé in 507, concerning the sons of one Ecdicius who wanted to return to Gaul where they had property; in a 1984 article Matthisen argued for the identification, pointing out that "not only is the Arvernian Ecdicius known to have been in Rome earlier, but Ecdicius also is a rare name."
- Sidonius Apollinaris, Epistulae III.3; translated by W.B. Anderson, Sidonius: Poems and Letters (Harvard: Loeb Classical Library, 1965), vol. 2 pp. 13ff
- Gregory, II.24; presumably referring to the skirmish mentioned by Sidonius (Epistulae, III.3.4). See also Bachrach, Bernard S. Merovingian Military Organization, 481–751. (Minneapolis: University of Minnesota Press, 1971), p. 16.
- A.H.M. Jones, The Later Roman Empire (Baltimore: Johns Hopkins, 1986), vol. 1 pp. 242f
- Sidionius, Epistulae, V.16.4; translated by W.B. Anderson, Sidonius, vol. 2 p. 225
- Jordanes, Gothica 240f. Translated by Charles C. Mierow, The Gothic History of Jordanes, 1915 (Cambridge: Speculum Historiale, 1966), pp. 118f
- "Why did Nepos replace Ecdicius with Orestes, when the first move of the latter was to seize Ravenna and raise a pretender to the throne? Who were the 'enemies' against whom Orestes was being sent (Jordanes)? Who 'sent' Orestes against Nepos (Auctuarium Hauniensis)? In default of additional information, one can only speculate. One possible reconstruction might be that the Senate of Rome was up to its old tricks and, as in the days of Avitus (455–456), became involved in an insurrection against a foreign emperor." De Imperatoribus Romanis: Julius Nepos: Expulsion
- Mathisen, "Emigrants, Exiles, and Survivors: Aristocratic Options in Visigothic Aquitania", Phoenix, 38 (1984), p. 166 and note