Cremona was a roman colony founded in 218 B.C., north of river Po. Its geographical position gave it military, civil and commercial importance in the Republican period. In 603 A.C. it was conquered and razed by Longobards. In 1098 it became a free town, and flourished thanks to the development of the water-way-commerce. After having supported Federico Barbarossa's policy for a long time, in 1167 it became a member of the Lombard League taking part in the battle of Legnano (1167). The political and economic importance of the medieval Cremona brought about a new urban development, which culminated in the construction of the superb complex of monuments forming the Palazzo Comunale Square and its imposing walls (1169 - 1187). In 1334 Cremona was conquered by Visconti and finally became a part of the dukedom of Milan from 1420 until the unity of Italy. In 1441 to celebrate the wedding between Bianca Maria Visconti and Francesco Sforza, Bianca Maria Visconti brought the town as a dowry and fostered its cultural and artistic renewal. This artistic production which had as protagonists Bonifacio and Benedetto Bembo in the second half of the fifteenth century went on also during the sixteenth century when Cremona was under the Spanish rule. In this period the great season of the refined Cremonensis mannerism grew up and had, among its significant protagonists, Camillo Boccaccino and Campi Brothers. The musical tradition, which had begun in the sixteenth century by Marcantonio Ingegneri reached the height of its glory with the "divine" Claudio Monteverdi. Cremona is famous for the art of making stringed instruments. The skilled founder was Andrea Amati. This activity was continued in XVII century by Nicolò Amati, Andrea's nephew and by Antonio Stradivari until he died in 1737.