Brian Penthièvre 1st Earl Cornwall 1040-1084

In 1069 an army commanded by Brian Penthièvre 1st Earl Cornwall [aged 29] defeated the sons of King Harold II of England around Northam in Devon.

Anglo-Saxon Chronicle. [1069] After this came Harold's sons from Ireland, about midsummer, with sixty-four ships into the mouth of the Taft, where they unwarily landed: and Earl Breon [aged 29] came unawares against them with a large army, and fought with them, and slew there all the best men that were in the fleet; and the others, being small forces, escaped to the ships: and Harold's sons went back to Ireland again.

Chronicon ex Chronicis by Florence and John of Worcester. 24th June 1069. Two of Harold's sons came again from Ireland, with sixty-four ships, and landing about the Nativity of St. John the Baptist [24th June] at the mouth of the river Tivy, fought a severe battle with Brian [aged 29], count of Brittany; after which they returned to the place whence they came.