The meadow brown butterfly (Maniola jurtina) is common across the British Isles during the summer months.
Males have smaller eye spots and much reduced orange patches, or none in the top example here which is likely to be a male. Presumably the bottom picture is a female which has an orange patch on each wing surrounding a black eye spot with a white pupil.
Regional variations in the spotting pattern on the wings have led to it being studied extensively by geneticists.
The caterpillar feeds on a wide range of grasses so typical habitats for this species are meadows, hedges and woodland rides.