After the military reforms of Gaius Maria, from the end of the 2nd century BC, the eagle finally established itself as the main symbol of the Roman legions. According to the religious beliefs of the Romans, the eagle was considered the incarnation of Jupiter and possessed supernatural military power.
Legion standard - "Eagle" (Aquila) symbolized the fighting spirit (genius) of the legion. In a military camp, he was installed in a special room - a sanctuary located near the commander's tent. The "Eagle" was under the personal responsibility of the senior centurion, the commander of the first century, which included the senior standard bearer (aquilifer), who wore the "Eagle".