[citation needed] The green iridescence of the wings has been found to be due to three-dimensional photonic structure of the scales and is the subject of much research.

The following descriptions are from Charles Thomas Bingham (1907) The Fauna of British India, Including Ceylon and Burma, Butterflies Volume 2.

Hindwing: basal area margined outwardly by a narrow irregularly sinuous band devoid of green scaling, succeeded by an upper discal bright chrome-yellow patch that spreads from base of interspace 3 across the apex of the cell and bases of interspaces 4 and 5 to the costa; this patch is bluntly angulated outwards in interspace 5, stained with orange anteriorly and bordered outwardly by black which is widest above; below the patch a white line extends to the dorsum; the postdiscal area is deep dark green, margined inwardly by diffuse dark grey and followed outwardly by a subterminal series of lunular markings, the tornal and upper two or three of which are yellow, the rest bright green; tail tipped with yellow.

Antennae dark red; head, thorax and abdomen black, covered somewhat densely with green hairs and scales.

Underside similar to the underside in the male, but on both forewing and hindwing the areas coloured with rich ochraceous and yellow are grey, with the exception of a well-marked moderately broad subterminal band on the forewing which is of a dull ochraceous colour; on the hindwing the grey discal area extends right up to the apical lunule of the subterminal series.

Mr. Elwes says that in Sikkim this insect is only found in the forest region from about 6,000 to 10,000 feet (1,800 to 3,000 m) elevation, and that "it is most difficult to capture on account of its remarkably strong, rapid and dashing flight, and its habit of resting on high trees from which it flies only during a few hours of the morning" (Elwes, Transactions of the Entomological Society of London 1888, p. 421).

The butterfly is found in small pockets of Nepal, Bhutan and along the Eastern Himalayas in India (West Bengal, Meghalaya, Assam, Sikkim and Manipur).

Protection enforcement in these countries not being effective; it is hunted and collectors pay high prices.

[4]: 19 The Kaisar-i-Hind is a high-altitude forest species[4]: 19  which occurs at medium and higher elevations in the Himalayas from 6,000 to 10,000 feet (1,800 to 3,000 m) in well-wooded terrain[citation needed].

When overcast, males are known to descend and sit on low vegetation, where its disruptive, dull underside colouration makes it difficult to distinguish.

[3][7][8] The three-dimensional photonic structure has been examined by transmission electron tomography and computer modelling to reveal naturally occurring "chiral tetrahedral repeating units packed in a triclinic lattice" (Argyros et al., 2001), the cause of the iridescence.