The Common Earl (Tanaecia julii), as the name suggests, is a relatively common butterfly with a wide distribution, including India, Bhutan, Myanmar, Thailand, China, West Malaysia and Sumatra. It is a butterfly I see regularly whilst walking in Doi Suthep–Pui National Park, Chiang Mai, Thailand, and all of these photographs were taken there, at different times.
There are three subspecies, but the one which occurs in Chiang Mai province is Tanaecia julii subsp. odilinia (1). The males have lovely chocolate-brown coloured wings, with a broad blue margin on the hind wing. They look to me like they have been dipped in blue paint!
The females are slightly larger, with prominent white marks or spots on the forewing and no blue band on the hindwing. As if to compensate, they have more blue than the males on the undersides of their hindwings! See below.
What is striking about both sexes of this butterfly, are their lovely green eyes! The males often rest on foliage in the sunshine, where they are relatively easy to photograph, although they do fly off easily if disturbed. They also have a green proboscis to match their eyes!
1) Butterflies of Thailand by Pisuth Ek-Amnuay. ISBN 978-9742891862