'Aquileia' (
Friulian ''Aquilee'') is an
ancient Roman city in what is now
Italy, at the head of the
Adriatic at the edge of the lagoons, about 10 km from the sea, on the river Natiso (modern
Natisone), the course of which has changed somewhat since Roman times.

A view of the archaeological area of Aquileia.
History
:''For the ecclesiastical history, see
patriarchate of Aquileia''
Aquileia was founded by the
Romans in 180/
181 BC on the narrow strip between the mountains and the lagoons, as a frontier fortress on the north-east, during the
Illyrian Wars, as a means of checking the advance of that warlike people, not far from the site where in 183 BC
Gaulish invaders had attempted to settle. The colony was led by two men of
consular and one of
praetorian rank, and 3000 ''pedites'' (infantry) formed the bulk of the settlers. Some scholars believe that Aquileia had been a center of
Venetia even before the coming of the Romans.
It was probably connected by road with ''Bononia'' (
Bologna) in
173 BC; and subsequently with ''Genua'' (
Genova) in
148 BC by the ''
Via Postumia'', which ran through
Cremona, Bedriacum and
Altinum, joining the first-mentioned road at Concordia, while the construction of the ''
Via Popilia'' from Rimini to Ad Portum near Altinum in
132 BC improved the communications still further.
In
169 BC, 1,300 more families were settled there as a reinforcement to the garrison. The discovery of the gold fields near the modern
Klagenfurt in
130 BC ★ class=wikiexternal target=_blank>.html#6.12 (Strabo iv. 208) brought it into notice, and it soon became a place of importance, not only owing to its strategic position, but as a centre of trade, especially in agricultural products. It also had, in later times at least, considerable brickfields.
It was originally a
Latin colony, but became a ''
municipium'' probably in
90 BC. Citizens were ascribed to the Roman tribe Velina. The customs boundary of Italy was close by in
Cicero's day. It was plundered by the
Iapydes under
Augustus, but, in the period of peace which followed, was able to develop its resources. Augustus visited it during the Pannonian wars in 12‑10 BC and it was the birthplace of
Tiberius' son by Julia, in the latter year.
It was the starting-point of several important roads leading to the north-eastern portion of the empire — the road (''
Via Iulia Augusta'') by ''Iulium Carnicum'' to Veldidena (mod.
Wilten, near
Innsbruck), from which branched off the road into
Noricum, leading by Virunum (Klagenfurt) to Laurieum (Lorch) on the
Danube, the road into
Pannonia, leading to Aemona (
Ljubljana) and Sirmium (
Sremska Mitrovica), the road to Tarsatica (near Fiume, now
Rijeka) and Siscia (
Sisak), and that to Tergeste (
Trieste) and the
Istrian coast.
Its commerce grew rapidly, and when
Marcus Aurelius made it (168) the principal fortress of the empire against the barbarians of the North and East, it rose to the acme of its greatness and soon had a population of 100,000. In the war against the
Marcomanni in
167, the town was hard pressed; the fortifications had fallen into disrepair during the long peace. In
238, when the town took the side of the Senate against the Emperor
Maximinus Thrax, they were hastily restored, and proved of sufficient strength to resist for several months, until Maximinus himself was assassinated.
The
4th century marks, however, the greatest importance of Aquileia; it became a naval station and, probably, the seat of the ''
corrector Venetiarum et Histriae''; a mint was established here, the coins of which are very numerous, and the bishop obtained the rank of
Patriarch. A council held in the city in 381 was only the first of a series of
Councils of Aquileia that have been convoked over the centuries.
An imperial palace was constructed here, in which the emperors after the time of
Diocletian frequently resided; and the city often played a part in the struggles between the rulers of the 4th century: In
340, Emperor
Constantine II was killed under its walls while attempting to take the city from his younger brother
Constans.
At the end of the century,
Ausonius enumerated Aquileia as the ninth among the great cities of the world, placing
Rome,
Mediolanum and
Capua before it, and called it "''moenibus et portu celeberrima.''" In
452, however, it was so utterly destroyed by
Attila's Huns, that it was afterwards hard to recognize its original site. The Roman inhabitants, together with those of smaller towns in the neighborhood, fled to the lagoons, and so laid the foundations of the city of Venice. Yet Aquileia arose again, but much diminished and continued to exist until the
Lombard invasion of
568, and was once more destroyed (590) by the Lombards. After this the patriarchate was transferred to
Grado.
It came under the Dukes of
Friuli, was again a city of the Empire under
Charlemagne. In the eleventh century Aquileia became a feudal possession of its patriarch, whose temporal authority, however, was constantly disputed and assailed by the territorial nobility.
In
606 the diocese was divided into two parts, and the patriarchate of Aquileia, protected by the
Lombards, was revived, that of Grado being protected by the
exarchate of Ravenna and later by the
Doges of Venice.
In
1027 and
1044 Patriarch
Poppo of Aquileia entered and sacked Grado, and, though the Pope reconfirmed the Patriarch of the latter in his dignities, the town never recovered, though it continued to be the seat of the Patriarchate until its formal transference to Venice in
1450.
The seat of the patriarchate of Aquileia had been transferred to
Udine in
1238, but returned in
1420 when Venice annexed the territory of Udine. It was finally suppressed in
1751, and the sees of Udine and
Gorizia (Görz) established in its stead.

Interior of the Cathedral, with the mosaic pavement.

Ancient mosaic in the Cathedral.

The archaeological walk.
Main sights
Cathedral
The Cathedral of Aquileia is one of the most important edifices of Christianity. It is a flat-roofed basilica erected by Patriarch Poppo in
1031 on the site of an earlier church, and rebuilt about
1379 in the
Gothic style by Patriarch Marquad.
The façade, in Romanesque-Gothic style, is connected by a portico to the ''Church of the Pagans'', and the remains of the 5th century Baptistry. The interior has a nave and two aisles, with a noteworthy mosaic pavement from the 4th century. The wooden ceiling is from 1526, while the fresco decoration belongs to various ages: from the 4th century in the St. Peter's chapel of the apse area; from the 11th century in the apse itself; from the 12th century in the so-called "Crypt of the Frescoes", under the presbytery, with a cycle depicting the origins of Christianity in Aquileia and the history of
St. Hermagoras, first bishop of the city.
Next to the 11th century Romanesque Holy Sepulchre, at the beginning of the left aisle, is ths of different ages can be seen: the lowest is from a Roman villa of the age of
Augustus; the middle one has a typical ''cocciopesto'' pavemente; the upper one, bearing blackening from the Attila's fire, has geometrical decorations.
Externally, behind the 9th century campanile and the apse, is the ''Cemetery of the Fallen'', where ten unnamed soldiers of World War I are buried.
Ancient remains
The ancient buildings of Aquileia served as stone quarries for centuries, and no edifices of the Roman period remain above ground. Excavations have revealed one street and the north-west angle of the town walls, while the National Archaeological Museum (one of the most important museum of Ancient Rome in the world) contains over 2,000 inscriptions, statues and other antiquities, as well as glasses of local production and a numismatics collection.
The site of Aquileia, believed to be the largest Roman city yet to be excavated, is inscribed on the
World Heritage List.
Others
In the Monastero fraction is a 5th century Christian basilica, later a Benedictine monastery, which today houses the Paleo-Christian Museum.
See also
★
Aquileian rite concerning the schism that created the patriarchate
★
Councils of Aquileia
★
List of Aquileia Bishops and patriarchs
★
Acaste Bresciani
Sources and references
★
Catholic Encyclopedia
★ Neher in Kirchenlexikon I, 1184-89
★ De Rubeis, ''Monumenta Eccles. Aquil.'' (Strasburg, 1740)
★
Ferdinando Ughelli, ''Italia Sacra'', I sqq.; X, 207
★ Cappelletti, ''Chiese d'Italia'', VIII, 1 sqq.
★ Menzano, ''Annali del Friuli'' (1858-68)
★ Paschini, ''Sulle Origini della Chiesa di Aquileia'' (1904)
★ Glaschroeder, in Buchberger's Kirchl. Handl. (Munich, 1904), I, 300-301
★
Hefele, Conciliengesch. II, 914-23.
★ For the episcopal succession, see
P. B. Gams, ''Series episcoporum'' (Ratisbon, 1873-86), and
Eubel, ''Hierarchia Catholica Medii Aevi'' (Muenster, 1898).