In the 5th century before Christ the Celts settled down in the site of what is today Milan. (To this date one can notice the Gallic influence in the dialect of the people of Milan.) The area was conquered by the Romans in 223 BC, and the colony was granted Roman municipal law in 89 BC. The antique town of Mediolanum became the residence of the western part of the Empire in 293 AD when Diocletian appointed Augustus Maximian as its regent. Under Ambrogio (374-397) Milan became the most important diocese in the Roman empire (355 Council of Milan) and soon the largest town in Italy. During the migration of nations Milan was conquered by the Huns, Ostrogoths and Lombards. In 774 it became Frankish (Charlemagne was crowned with the Lombard kings’ iron crown), in the 12th century it was the leader in the City League against Ghibellines. In 1162 it was destroyed by the Emperor Frederic I (Barbarossa), and rebuilt in 1167. The town came under the rule of the Visconti in 1395, under the Sforza in 1450, under the Spanish Habsburgs in 1535, and under the Austrian Habsburgs in 1714. In 1859 Milan became part of the newly founded Kingdom of Italy and up to this date has experienced an upswing to become the industrial metropolis of Italy.