On the outbreak of war in 1866 he assumed command of a volunteer army and, after the defeat of the Italian troops at Custozza, took the offensive in order to cover Brescia.
He fought with success in Italy, but was chiefly noted for the severity he showed in suppressing and punishing a rising in Brescia.
In matters of doctrine the pope supported Bernard of Clairvaux in his prosecution of Abelard and Arnold of Brescia, whom he condemned as heretics.
In this lower part it receives the smaller streams of the Mella, which flows by Brescia, and the Chiese, which proceeds from the small Lago d'Idro, between the Lago d'Iseo and that of Garda.
In northern and central Italy, except in the province of Brescia, the agrumi are almost non-existent.