In ancient times the area of what is today Ticino was settled by the Lepontii, a Celtic tribe. Later, probably around the rule of Augustus, it became part of the Roman Empire. After the fall of the Western Empire, was ruled by the Ostrogoths, the Lombards and the Franks. Around 1100 CE it was the centre of struggle between the free communes of Milan and Como: in the 14th century it was definitively acquired by the Visconti, Dukes of Milan. In the 15th century the Swiss Confederates conquered the valleys south of the Alps in three separate conquests.