Guelph–Ghibelline Factional Conflict in Italy

Timeline

1. 1371–1377Central Italy (Rome–Florence) · TuscanyFlorence, Siena, and other city-states upheld the Guelph tradition and supported papal authority, while Milan's Visconti family was often regarded as the leading Ghibelline power. In 1377 Gregory XI transferred the papacy from Avignon back to Rome, restoring the pope's political influence in Italy and sharpening the confrontation with Milan and other powers.
2. 1375–1378Border of Tuscany and Lombardy · ItalyWith papal backing, Florence formed a league and declared war on Milan in the name of the "Eight Saints," with mercenaries such as John Hawkwood campaigning in central Italy. The war continued around the time of the 1378 Great Schism; although Milan was not decisively defeated, the Visconti's expansion was checked and resources were drained on all sides.
3. 1378–1380Florence · TuscanyInternal unrest such as Florence's 1378 Ciompi Revolt overlapped with the Guelph–Ghibelline conflict and foreign wars. Noble factions exploited domestic and external crises to consolidate their rule, while lower-class demands were suppressed. Amid the Church Schism, Italian city-states increasingly chose sides along political interests, and factional labels gradually gave way to naked power politics.