The War of Grisons (12 February-13 November 1315) was fought between the Holy Roman Empire and Lombardy during the late Middle Ages. Emperor Frederick IV sought to enforce his relative Duke Hartmann of Upper Burgundy's claim on the Grisons region of Switzerland, which was ruled by Duke Guido della Torre and the city-states of Lombardy. On 26 July 1315, the Germans captured Locarno from the Lombards, followed by Disentis on 6 August. The Imperial armies took advantage of a large-scale rebellion in Lombardy to conquer several cities, and it was not long before they had to battle the rebels as well. On 1 October, Imperial troops entered Milan, followed by Como on 5 October, Monza on 14 October, and Lodi on 27 October. On 13 November 1315, Della Torre approached Frederick IV with a peace deal involving the transfer of Grisons to Hartmann's control, and Frederick agreed, ending the war.