John I of Brittany

John I the Red (c. 1217–1286), named for the colour of his beard, was Duke of Brittany from 1221, under the regency of his father Peter Mauclerc until 1237. In 1236 he married Blanche, daughter of King Theobald I of Navarre, who bore his successor John II.

In 1240 he expelled the Jews from the duchy and cancelled debts owed to them. Henry III made him Earl of Richmond in 1268, and he joined Louis IX on the Eighth Crusade in 1270, surviving the plague that killed the king. He died on 8 October 1286.