From the UK:

By Ferry/Car
From Portsmouth to St. Malo. Then approx. 4 1/2 hours easy drive via Rennes, Nantes and Niort.

By Plane
Stansted to: Poitiers, Angoulme, Limoges or La Rochelle.
Birmingham to Poitiers.

By Train
Eurostar to Paris, then TGV to Angouleme or Ruffec.