On 24 May 843 the Battle of Blain aka Messac was a battle between Brittany and the County of Nantes over control of Nantes which, at that time, was controlled by the Frankish Kingdom. The Franks were defeated.

Lambert Guideschi II Count Nantes commanded the Breton army.

Renaud Count of Herbauges, Poitiers and Nantes, who commanded the army of Nantes, was killed the following day.