Galeazzo's brother Bernabò Visconti, whom he fought alongside when challenging the papacy, has also been considered a tyrant. Bernabò was particularly brutal towards the church and was listed as an enemy as a result. Together, the brothers fought against Pope Urban V and Pope Gregory XI and were both excommunicated by the papacy in 1373. Military figures such as John Hawkwood and Amadeo of Savoy were hired to attack the Visconti brothers and their city-states, Pavia and Piacenza. However, Amadeo of Savoy helped to end the long-standing battle between the papacy and the Visconti brothers after recognizing the increasingly oppressive nature of the papacy, which hoped to destroy the Milanese family at all costs, and which did not recognize their legitimate territorial dominions. Galeazzo II's marriage to Bianca of Savoy, re-formed an alliance with the House of Savoy and Gregory XI was compelled to sign a peace treaty with Galeazzo II and Bernabò in the spring of 1375. Peace between Pope Gregory XI and the Visconti family was transient in that soon after their agreement, Bernabò's alliance with Florence, who had a longstanding struggle with the papacy, called for their support in the War of Eight Saints, waged against Gregory XI. Galeazzo II fought against the papacy alongside his brother until his death in 1378.