I have seen many of these, but not always in great condition. They are widespread across Europe, and can be distinguished by the faintly concave forewing upperside outer margin and the enlarged submarginal crescent in S3.

The male, top left was photographed in the south of France, whilst doing my best to cling onto a steep slope of loose stone. The underside butterfly photo, below left, was imaged in a gnat ridden clearing in Northern Italy. The two female shots below came from the Swiss Valais and the Pyrenees, quite widespread really !!