The following reconstruction of a 13th century Anglo-Poitou family is an illustration of how useful and encouraging internet sources can be.
Families and seigniories
Three generations of the Anglo-Poitou family of Vivonne, from 13th century “Poitevin mercenary captain” to 14th century “recalcitrant lady”
21 December 2008, by Margaret
1758 - "Ban" i.e. list of the members of the nobility of Saintonge
26 June 2007, by Pierre
"... in the present circumstances, when the English seem to be intending to attack the coasts of Poitou, Saintonge and country of Aunis : His Majesty is convinced that the nobility of these provinces will have the same zeal to be in his service ..."
The English, to attack Poitou, Saintonge and Aunis ?
As far as we know, they have always been keen of these provinces ...