Near the Adriatic
coast 19 km S of Ancona and ca. 242 km N-NE of Rome,
on a strong and isolated hill (457 in above sea level) that
dominates the valley of the Musone, the approaches to S
Picenuin, and the roads to Rome. The area has been continuously inhabited since the Stone Age. Senonese Gauls
penetrated it in the 4th c. B.C. despite tough Picene resistance.
Gallic necropoleis have been found W of Osimo on the
road to Iesi (Aesis). They were excavated just before
WW I, and the wealth of objects unearthed now constitutes one of the glories of the Museo Nazionale delle
Marche in Ancona: they include vitreous vases, objects
in amber, ivory, and bronze, numerous imports from
Magna Graecia and Etruria, and splendid specimens of
Gallic jewelry, some of it in gold.
Early in the 3d c. B.C. the Roinans helped the Picenes
to expel the Senones, only to make themselves the masters of the whole region shortly afterwards (268 B.C.).
Later they established a Roman colony at Auximum,
exactly when is uncertain: Velleius Paterculus (1.15.3)
assigns the colony to 157 B.C., but he is almost certainly
wrong. The foundation may belong to 128 B.C. The town
has always been of importance. In the civil war of 49 B.C.
it quickly sided with Julius Caesar against Pompey the
Great, despite the latter's large estates and considerable
influence in the neighborhood: the earliest inscription
found at Auxiinum, now in the Palazzo Comunale, names
Pompey as the town's patron is 52 B.C. (cf. also Plut.
. 6.3). It became a bishopric in the 4th c. and
changed hands more than once in the Gothic wars
The town walls, which apparently go back to the 2d c.
B.C., are the principal Roman monument at Auximuin.
They survive only in part but, as they evidently followed
the contours of the hill on which the town is perched,
the entire enceinte can be conjectured with some probability. Not a particularly large town-site (200-300 x 600-700 m), the total circuit of the walls may have been ca.
1700 in and the enclosed area something less than 16 ha.
The best surviving stretch of the walls is under the convent of S. Francesco on the N side of the town, a splendid
example, 200 m in length, of isodomic Roman opus quadratum. The rectangular blocks (1-1.6 m x 40-45 cm) are
of a hard local tufa. Twenty courses are still in situ, very
methodically laid, the blocks progressively smaller as they
rise. The walls, over 2 m thick at the bottom, attained
a height of 10 m or more.
Conforming to the Italic pattern, the town had three
gates: to the NW, Porta Vetus Auximuin, for the road
to Ancona; to the S, Porta Musone, for the roads to
Aesis and Cingulum; to the E, the gate for the road to
Potentia probably stood at the Largo S. Agostino.
A postern near the NE corner of the town leads to the
imposing ruins of the Fonte Magna, a structure of apsidal
appearance implausibly assigned to Pompey the Great
(whence its name): together with a nearby cistern and
some connecting underground tunnels (of Augustan
date ?) it formed part of a complex that, according to
. 2.23-28), provided the town's water
The streets at the modern town center partly preserve
the Roman plan, Corso Mazzini corresponding to the
decumanus maximus and Via del Sacramento to the
cardo inaxiinus. The Arx, in the Gomero or NW quarter
of Osimo, had its own wall of opus quadratum, remains
of which can still be seen in the bishop's palace; it also
had a concrete building, of rectangular shape (4 x 9 m)
but unknown purpose. The forum was farther W at
the Piazza del Comune, where numerous finds have
been made, starting in 1487; no Roman buildings, however, remain, at least above ground. The Capitolium may
have stood where the Cathedral now is: local tradition
places a Temple of Jupiter there. Vaulted and circular
remains, in Piazza Don Minzoni and Via S. Francesco
respectively, perhaps belonged to baths. Private houses
have not been found although mosaic pavements have
occasionally come to light.
Ever since 1741 antiquities have been housed for the
most part in the atrium, portico, and cortile of the Palazzo Comunale. They include numerous inscriptions and
architectural fragments, but above all an important and
representative collection of Roman sculpture, mostly of
the Early Empire. Its chief pieces are: ten headless marble statues, slightly larger than life size, said to have
once adorned the forum; a limestone bas relief depicting
the town magistrates and a lictor; and a well-preserved
and remarkably realistic head of an old man of the 1st c.
B.C. There are antiquities also in the Palazzo Balleani-Baldeschi, in the Villa Barbalarga outside the Porta Musone, and in the Cathedral crypt (the usual Roman columns and Early Christian sarcophagi).
Traces of Roman centuriation have been found in the
neighboring valley of the Musone.
H. Nissen, Italische Landeskunde
(1902) II, 418f; G. V. Gentili, Auximum
(= Ser. I, Vol.
XV in the Italia Romana: Municipi e Colonie
(1955) with good bibliographyMPI
; C. Grillantini, La
Storia di Osimo
(1957); E. T. Salmon, Roman Colonization under the Republic
E. T. SALMON