Why did the dukes of Montfort try to keep Brittany neutral during the Hundred Years’ War?

The dukes of the House of Montfort sought to maintain neutrality during the Hundred Years’ War primarily to preserve the autonomy and stability of Brittany as an independent duchy.

Following a mid-14th-century civil war for control of the duchy—which had drawn in both English and French support for rival claimants—the Montforts eventually secured the title of duke. By attempting to remain neutral during the remainder of the broader conflict between England and France, they aimed to protect their hard-won position and prevent their territory from becoming a perpetual battleground for foreign powers. This strategy was consistent with the long-standing efforts of the Breton dukes throughout the Middle Ages to assert their independence and resist the centralizing pressures of their powerful neighbors.1