The first duke of Brittany, Nominoe, defeats the Frankish king Charles the Bald at the Battle of Ballon near Redon.

Brittany is a peninsula, historical country and cultural area in the north-west of modern France, covering the western part of what was known as Armorica in Roman Gaul. It became an independent kingdom and then a duchy before being united with the Kingdom of France in 1532 as a province governed as a separate nation under the crown. Brittany is the traditional homeland of the Breton people and is one of the six Celtic nations, retaining a distinct cultural identity that reflects its history.

Nominoe or Nomenoe was the first Duke of Brittany from 846 to his death. He is the Breton pater patriae and to Breton nationalists he is known as Tad ar Vro.

Charles the Bald, also known as Charles II of West Francia, was a 9th-century king of West Francia (843–77), King of Italy (875–77) and emperor of the Carolingian Empire (875–77). After a series of civil wars during the reign of his father, Louis the Pious, Charles succeeded, by the Treaty of Verdun (843), in acquiring the western third of the empire. He was a grandson of Charlemagne and the youngest son of Louis the Pious by his second wife, Judith.

The Battle of Ballon took place on 22 November 845 between the forces of Charles the Bald, king of West Francia, and Nominoë, Duke of Brittany. Nominoë was appropriating border territory and opposing Charles' attempt to impose Frankish authority. Nominoë defeated Charles, initiating a period of Breton expansion and consolidation of power.