The Battle of Conquereuil was fought on July 27, 992 AD between the Bretons under Duke Conan I of Rennes and the Angevins under Duke Fulk the Black.[1]
Duke Conan had the city of Nantes under siege, when he learned that Duke Fulk was marching with an army to relieve the city. Conan raised the siege and began marching his troops back towards Rennes. Once he had realized that his army could not outrun Fulk, Conan halted at Conqueruil and prepared the battlefield, digging pits and ditches which were flooded by the water of nearby swamps and then hidden by covering them lightly with sod, and behind this prepared earthworks which had their flanks secured by the swamps.[2]
The Angevins attacked, and Breton troops lured the Angevin knights into the flooded pits by feigning flight. The Bretons then counterattacked and drove the Angevins back in disarray. During a lull in the battle, during which the Bretons apparently prematurely considered the battle won, Fulk reorganized his army, attacked the Bretons again, and routed them, killing Conan in the process.
Another version of the story suggests that the Breton counterattack was successful and drove the Angevins back in disarray. In the midst of a Breton pursuit, Conan removed his armour because it was hot, and some Angevin knights in a wood saw him, charged the unarmoured duke, and killed him, turning the battle decisively in the favor of the Angevins.
Bradbury, Jim. The Medieval Siege. Boydell Press, 1992, p. 62.
Bachrach, Bernard S. Fulk Nerra, the Neo-Roman Consul, 987-1040, 1993, p. 101