Adonis blues are another species of butterfly which you are very unlikely to see in this part of England: they are restricted to the limestone/chalk hills of the south on this side of the Channel.
The limestone cliffs of the Vézère valley seem to be just the ticket for them. They headed for flowering bushed even in the centre of the village of les Eyzies.
This one is a more showy male. The females have a brown pattern.