To me its looks close to a “Ringlet Butterfly” but my book has a clearer photo and they have a white border around the edge of the wings. But thye do have those Eyespots at the base. Taken from “Collins Complete Irish Wildlife Book” Introduction By Derek Mooney an invaluable book which dont cost a lot.
Old age, time, fighting (Speckled Wood is very territorial), weather, wear and tear. Most of the butterflies we see during the summer only live a few weeks tops. However, they may have lived for caterpillars and pupae for months previous to that. Noely had a great shot of a pupae in the marco setion a few months back. I think it was titled “waiting”. I have plenty of shots-examples of specimens on their last legs (wings) as well though.