I'll forgive you if you don't recognise this butterfly. It confused me at first.
It is actually a ringlet - Aphantopus hyperantus but the rings that give it its name are missing and only reduced white pupils remain.
There is a named aberration (ab. arete) which has all rings absent but although this one is missing all rings on the hind wing, there appears to be a single faint ring on the forewing peeking out from behind the hindwing.
This individual also has a slightly mis-shapen lower margin to its hindwing.