The Carni are usually considered a Gaulish tribe, although some associate them with the Venetic peoples, a group closely related to but probably distinct from the Celts.

Their area of settlement isn't known with precision.

Strabo confines them to the mountains, while Ptolemy assigns them two cities near the Adriatic coast.

They are likely eponymous of the regions of Carnia, Carniola and Carinthia.

The first historical date related to the arrival of the Carni is 186 BCE, when some fifty thousand Carni, composed of armed men, women and children, descend from the northeast corner of transpadane Italy towards the plains (in which they previously used to winter) and on a hill they establish a stable defensive settlement, Akileja, situated at the head of the Adriatic at the edge of the lagoons, about ten kilometers from the sea, on the river Natiso (modern Natissa).

Rome founds a colony at Aquileia, on the narrow strip of land between the mountains and the lagoons, in 181/180  BCE as a frontier fortress in the northeast to check the advance of the warlike Illyrians, as well as the hostile tribes of Carni and Istri, not far from the site where in 183 BCE Gaulish invaders had attempted to settle.

It is likely that Aquileia had been a center of Venetia even before the coming of the Romans, and Aquileia's strategic military position also serves to promote the Venetic trade in amber imported from the Baltic.

The Latin colony is established by the triumvirate of Publius Scipio Nasica, Caius Flaminius, and Lucius Manlius Acidinus, two of whom are of consular and one of praetorian rank.

They lead three thousand pedites (infantry), mainly from Samnium, who with their families form the bulk of the settlers.

They will shortly be supplemented by native Veneti.

Aquileia will soon connected by road with Bononia (Bologna), probably in 173 BCE; and subsequently with Genua (Genova) in 148 BCE by the Via Postumia, which would run 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 BCE will improve the communications still further.

In 169 BCE, thirteen hundred more families will be settled in the town as a reinforcement to the garrison.

The discovery of the gold fields near the modern Klagenfurt in 130 BCE (Strabo iv.

208) will bring it into wide notice, and it will soon became a place of importance, not only owing to its strategic position, but as a center of trade, especially in agricultural products.

It also had, in later times at least, considerable brickfields.

The original Latin colony will become a municipium, probably in 90 BCE, its citizens ascribed to the Roman tribe Velina.

The Romans have by 181/180 BCE forced back the Carni to the mountains, destroyed their settlement and established a defensive settlement not far from where the Gaulish invaders had attempted to settle, on land along the Natiso south of the Julian Alps but about eight miles north of the lagoons.

The colony is to serve as a frontier fortress to protect the Veneti, faithful Roman allies, during the Illyrian Wars and act as a buttress to check the advance of other warlike people, such as the hostile Carni and Histri tribes.

Aquileia is established with Latin rights by the triumvirate of Publius Cornelius Scipio Nasica, Caius Flaminius, and Lucius Manlius Acidinus, two of whom are of consular and one of praetorian rank.

They lead three thousand pedites (infantry), mainly from Samnium, who with their families form the bulk of the settlers; they are soon supplemented by native Veneti: Aquileia's strategic military position also serves to promote the Venetic trade in amber imported from the Baltic.

Aquileia is connected by road with Bologna probably in 173 BCE.

Fifteen hundred more Latin colonists with their families are settled in the town in 169 BCE as a reinforcement to the garrison.

…Aquileia.

The military occupation of Liguria depends upon this road, and several of the more important towns owe their origin largely to it.

…the coemperors establish their headquarters at Aquileia.

Supervising a reorganization of the defenses of Italy and the Illyricum, Marcus and Lucius raise two new legions, Legio II Italica and Legio III Italica, and cross the Alps into Pannonia.

The Marcomanni and the Victohali have crossed the Danube into the province, but, at least according to the Historia Augusta, the approach of the imperial army to Carnuntum is apparently sufficient to persuade them to withdraw and offer assurances of good conduct.

Historian William McNeill will assert that the Antonine Plague and the later Plague of Cyprian (251–ca. 270) were outbreaks of two different diseases, one of smallpox and one of measles, not necessarily in that order.

he severe devastation to the European population from the two plagues may indicate that people had no previous exposure to either disease, which brought immunity to survivors.

Other historians believe that both outbreaks involved smallpox.

The latter view is bolstered by molecular estimates that place the evolution of measles sometime after CE 500.

The Greek physician and writer Galen had traveled from Rome to his home in Asia Minor in 166, during the epidemic, and returns to Rome in 168 when summoned by the two Augusti—the co-emperors Marcus Aurelius and Lucius Verus; he is present at the outbreak among troops stationed at Aquiléia in the winter of 168/69.

Galen briefly records observations and a description of the epidemic in the treatise Methodus Medendi, and his other references to it are scattered among his voluminous writings.

He describes the plague as "great" and of long duration and mentions fever, diarrhea, and pharyngitis, as well as a skin eruption, sometimes dry and sometimes pustular, appearing on the ninth day of the illness.

The information provided by Galen does not clearly define the nature of the disease, but scholars have generally preferred to diagnose it as smallpox.

The two emperors return to Aquileia for the winter, but Lucius Verus dies on the way, in January 169.

Marcus returns to Rome to oversee his co-emperor's funeral.

...Aquileia, the main Roman city of northeast Italy.

This is the first time hostile forces had entered Italy since 101 BCE, when Gaius Marius defeated the Cimbri and Teutones.

The army of Furius Victorinus, one of the two praetorian prefects, tries to relieve the city, but is defeated and its general slain.