The Horsfield's Baron is dimorphic, in that the male has a velvety black upperside with a broad bright blue marginal border on the hindwings and the female is pale greyish ochreous brown and is often confused with Tanaecia pelea (Malay Viscount) or one of the Euthalia species.

1st & 2nd photo: Khao Phanom Bencha National Park, Krabi, Thailand, 31 January 2013
3rd photo: Tub Kaek Beach area, Krabi, Thailand, 2 February 2013