John of Brittany was a nobleman born around 1286, known for his role as the Duke of Brittany. He was the son of John II, Duke of Brittany and Beatrice of England. John became Duke in 1341, during a time of political turmoil and conflict over the succession of the duchy. His reign was marked by struggles against the French crown and internal disputes among the Breton nobility. John of Brittany was also involved in the Hundred Years' War, aligning with the English at times. He died in 1399, leaving a legacy of both conflict and governance in Brittany.