On September 22, 66, Emperor Nero created the Legio I Italica. From the article:
"In the aftermath of the Roman–Parthian War of 58–63, Emperor Nero levied the I Italica with the name phalanx Alexandri Magni ("phalanx of Alexander the Great"), for a campaign in Armenia, ad portas Caspias - to the pass of Chawar. The sources mention the peculiar fact that the original legionaries were Italics, all over six feet tall. However, since the Jewish Revolt broke out a few weeks later, the projected Armenian campaign never took place. Also, the governor of Gaul, Gaius Julius Vindex, rose in revolt in early 68 and I Italica was redirected there, arriving just in time to see the end of the revolt. In the Year of the Four Emperors (69), after the death of Nero, the legion received the name I Italica and fought for Vitellius at the second Battle of Bedriacum, where the Vitellians were defeated by forces supporting Vespasian. The new emperor sent I Italica to the province of Moesia in 70. They encamped at Novae (modern Svishtov) which became the legions provincial base for centuries.
The legion served on campaign during the Dacian wars of Trajan. The legion was also responsible for bridge construction over the Danube. Building activities seem to have been an area of expertise for the legion. On 3 December 1969 a Roman votive altar was found at Old Kilpatrick on the Antonine Wall dating from around 140 A.D.[1] It has been scanned and a video produced.[2] The inscription mentions the First Cohort of Baetasians, previously known to have been at Bar Hill, and also Julius Candidus, a centurion from I Italica.
During the reign of Marcus Aurelius, Legio I Italica was involved in the wars against the Germanic tribes that threatened to cross the Danube. After a long war, the Romans had conquered much territory on the left side of the Danube. There Marcus Aurelius had intended to form a new province under governor Aulus Julius Pompilius Piso, commander of I Italica and IV Flavia Felix, but the revolt of Avidius Cassius in the East prevented the formation of the new province.
In 193, the Governor of Pannonia Superior, Septimius Severus claimed the purple and moved to Italia. I Italica supported Severus, but did not move to Italy. The legion fought against Severus' rival, Pescennius Niger, besieging Byzantium together with XI Claudia, fighting at Issus. The First possibly took part in the Parthian campaign of Severus (198).
In the 3rd century, during the rule of Caracalla, the legion participated in the construction of the Limes Transalutanus, a defensive wall along the Danube, which began near Novae. Under Alexander Severus, some vexillationes of the I Italica moved to Salonae, guarding the Dalmatian coast."