ARRETIUM (mod. Arezzo), an ancient city of Etruria, in the upper valley of the Arno, situated on the Via Cassia, 50 m. S.E. of Florentia. The site of the original city is not quite certain; some writers place it on the isolated hill called Poggio di S. Cornelio, 2 m. to the S.E., where remains of a fortified enceinte still exist (cf. F. Noack in Römische Mitteilungen, 1897, p. 186); while others maintain, and probably rightly, that it occupied the hill at the summit of the modern town, where the medieval citadel (fortezza) was erected, and which was enclosed by an ancient wall. Numerous Etruscan tombs have been discovered within the lower portion of the area of the modern town, which appears to correspond in site with the Roman (C.I.L. xi. p. 1082; G. Gamurrini in Notizie degli scavi, 1883, 262; 1887, 437). Vitruvius (ii. 8. 9) and Pliny (Nat. Hist. xxxv. 173) speak of the strength of its walls of bricks, but these have naturally disappeared. Many remains of Roman buildings have been discovered within the modern town, and the amphitheatre is still visible in the southern angle. Arretium appears as one of the cities which aided the Tarquins after their expulsion. It was an opponent of Rome at the end of the 4th and beginning of the 3rd century B.C., but soon sought for help against the attacks of the Gauls, against whom it was almost a frontier fortress. It was an important Roman base during the Hannibalic wars (though at one time it threatened defection - Livy xxvii. 21-24), and in 205 B.C. was able to furnish Scipio with a considerable quantity of arms and provisions (Livy xxviii. 45). In 187 B.C. the high road was extended as far as Bononia. Arretium took the part of Marius against Sulla, and the latter settled some of his veterans there as colonists. Caesar, or Octavian, added others, so that there are three classes, Arretini veteres, Fidentiores, and Iulienses. A considerable contingent from Arretium joined Catiline and in 49 B.C. Caesar occupied it. C. Maecenas  was perhaps a native of Arretium. Its fertility was famous in ancient times, and still more the red pottery made of the local clay, with its imitation of chased silver. The reliefs upon it are sometimes of considerable beauty, and large quantities of it, and the sites of several of the kilns, have been discovered in and near Arretium. It was also considerably exported. See Corp. Inscrip. Lat. xi. (Berlin, 1901) p. 1081, and Notizie degli scavi, passim (especially, 1884, 369, for the discovery of a fine group of the moulds from which these vases were made). The museum contains a very fine collection of these and a good collection of medieval majolica.
 The name Cilnius was apparently never borne by Maecenas himself, though he is so described, e.g. by Tacitus, Ann. vi. II, cf. Macrob. ii. 4, 12. The Cilnii with whom Maecenas was connected were a noble Etruscan family.
Note - this article incorporates content from Encyclopaedia Britannica, Eleventh Edition, (1910-1911)