Just after Christmas we decided to undertake an "exploring Châtellerault" expedition. Châtellerault is our nearest town but being in a different Department it is somewhere we hardly ever visit, the main exception being to try sort out France Telecom. (This is supposedly not possible, because of the difference in Department - but I suspect it has more to do with France Telecom being impossible to sort out.) The most recent expedition was mainly unsuccessful because most of the shops were shut, but this left us some time to visit some places we had read about but never visited.
The second battle was fought at Moussais la Battaille just south of Châtellerault, and near the Roman town now known as "Vieux Poitiers" (Old Poitiers). The ruins of Vieux Poitiers are being excavated, but the site wasn't open so we have written that down for another day. After getting misled by strange road-signage (this is France, get used to that peculiarity) we found the visitors centre for the battle - which is actually quite good. There is a lot of information boards, and although the language is a bit flowery (click on the picture on the left for full effect) quite a bit of information.
This battle is presumed to be important because it is where the Moors were defeated heavily enough to stop their conquest of France, and therefore the rest of Europe.
This has been the cause of much debate by people cleverer than me*, but one fact that can't be disputed is that after the battle Charles was sufficiently strong enough to add Aquitaine (previously held by Eudes of Aquitaine) to the Carolingian Empire. This meant that the Charles (who not only added territories, but the epithet "Martell" - the Hammer - to his name) held most of what is now considered France (there is a map here).
Wikipedia has a lot more on the battle.
*surely not!! I had better hear you cry