The following is a history of Milan, Italy.
Around 400 BC, the Celtic Insubres settled Milan and the surrounding region. In 222 BC, the Romans conquered the settlement, renaming it Mediolanum.
History tells us that Mediolanum (Milan), the Latinized form of Medhelanon, meaning "sanctuary", was founded by the Insubri Celts in 590 B.C. According to Titus Livy’s comments, the city was founded around 600 B.C. by Belloveso, chief of the Celtic tribe. Legend has it that Belloveso found a mythological animal known as the scrofa semilanuta (in Italian: "half-woollen boar") which became the ancient emblem of the city of Milan (from semi-lanuta or medio-lanum). Several ancient sources (including Sidonius Apollinaris, Datius, and, more recently, Andrea Alciato) have argued that the scrofa semilanuta is connected to the etymology of the ancient name of Milan, "Mediolanum", and this is still occasionally mentioned in modern sources, although this interpretation has long been dismissed by scholars. Nonetheless wool production became a key industry in this area, as recorded in during the early Middle Ages (see below).
Milan was conquered by the Romans in 222 B.C. due to its strategic position on the northern borders of the Empire. When Diocletian decided to divide the Empire in half choosing the Eastern half for himself, Milan became the residence of Maximian, ruler of the Western Roman Empire. The construction of the second city walls, roughly four and a half kilometers long and unfurling at today’s Foro Bonaparte, date back to his reign. After the abdication of Maximian (in 306 A.D.) on the same day in which Diocletian also abdicated, there were series of wars of succession, during which there was a succession of three emperors in just a few short years: first Severo, who prepared the expedition against Maxentius, then Maxentius himself in war against Constantine, and finally Constantine, victor of the war against Maxentius. In 313 A.D. the Emperor Constantine issued the Edict of Milan (Edict of Constantine), ending the persecutions against Christians.
The beginning of the 5th century was the start of a tortuous period of barbarian invasions for Milan. After the city was besieged by the Visigoths in 402, the imperial residence was moved to Ravenna. An age of decadence began which worsened when Attila, King of the Huns, sacked and devastated the city in 452 A.D. In 539, the Ostrogoths conquered and destroyed Milan during the Gothic War against Byzantine Emperor Justinian I. In the summer of 569, a Teutonic tribe, the Lombards (from which the name of the Italian region Lombardy derives), conquered Milan, overpowering the small Byzantine army left for its defence. Some Roman structures remained in use in Milan under Lombard rule.