s led to Milan granting all of the Leventina Valley to Pollegio to Uri in 1441. Following the death of Duke Filippo Maria Visconti in 1447, Bellinzona was in the middle of the succession crisis between Franchino Rusca of Locarno and Heinrich of Val Mesolcina, who were allied with Uri and the Ambrosian Republic in Milan. The war following the succession crisis lasted nearly three years until Francesco I Sforza seized power in Milan. Bellinzona quickly accepted the new Sforza dynasty and the peace and stability that followed.
The peace was broken again in 1478 when the Swiss once again attacked Bellinzona unsuccessfully. However Swiss pride was restored by the Battle of Giornico which followed, where a force of 600 Swiss soldiers defeated 10,000 Milanese troops. Following the attack, Milan built the Sasso Corbaro either on the site of a tower which had been built nearly a century before. The other two castles were strengthened and the Murata wall across the valley was rebuilt. Much of the modern castles and fortifications date from this period of construction in the late 15th century.
An associate of the Swiss Confederation
In 1499 nearly one and a half centuries of Milanese rule ended with the invasion of Milan by Louis XII of France. He captured Bellinzona and fearing an attack by the Swiss, fortified the Castelgrande with 1000 troops. Throughout the winter of 1499/1500 unrest in Bellinzona grew, until January when an armed revolt of the citizens of Bellinzona drove the French troops from the city. Following the capture and execution of Ludovico Sforza in April 1500 and seeking protection from France, Bellinzona joined the Swiss Confederation on 14 April 1500, as a condominium under the joint administration of Uri, Schwyz and Nidwalden. Following the Napoleonic invasion of Switzerland in 1798, Bellinzona was the capital of the canton of Bellinzona within the Helvetic Republic (1798�1803).
