This delightful little butterfly is best-known for having two different looking forms, levana and prorsa that represent the spring and summer broods respectively.
The first two photos show the spring form levana; individuals are primarily orange in colour, giving them the appearance of a small fritillary.
The last three photos show the summer form prorsa; individuals are blackish with white markings and look more like a very small White Admiral (Limenitis camilla).

1st photo: Naardermeer, Naarden, The Netherlands, 26 April 2014
2nd photo: Naardermeer, Naarden, The Netherlands, 2 May 2015
3rd photo: 's Graveland, The Netherlands, 11 July 2011
4th photo: Staverden, The Netherlands, 26 July 2016