Emperor Avitus enters Italy with a Gallic army and consolidates his power.

Eparchius Avitus was Roman emperor of the Western Empire from July 455 to October 456. He was a senator of Gallic extraction and a high-ranking officer both in the civil and military administration, as well as Bishop of Piacenza.

Italy, officially the Italian Republic, is a country in Southern and Western Europe. It consists of a peninsula that extends into the Mediterranean Sea, with the Alps on its northern land border, as well as nearly 800 islands, notably Sicily and Sardinia. Italy shares land borders with France to the west; Switzerland and Austria to the north; Slovenia to the east; and the two enclaves of Vatican City and San Marino. It is the tenth-largest country in Europe by area, covering 301,340 km² (116,350 sq mi), and the third-most populous member state of the European Union, with nearly 59 million inhabitants. Italy's capital and largest city is Rome; other major cities include Milan, Naples, Turin, Palermo, Bologna, Florence, Genoa, and Venice.

September 21 is the 264th day of the year in the Gregorian calendar; 101 days remain until the end of the year.