The Apatura iris, known as the Purple Emperor, is a striking butterfly found in deciduous woodlands across Europe. It is known for its iridescent purple wings, seen mostly in males, and its elusive nature. The species feeds on tree sap, dung, and carrion, playing a unique role in nutrient recycling.

Apatura iris, commonly known as the Purple Emperor, is native to Europe and parts of Asia. Its geographical distribution spans from the United Kingdom and southern Scandinavia, across central and eastern Europe, to northern Spain and parts of Russia. It is also found in temperate regions of Asia, including parts of Kazakhstan and Siberia.

The Purple Emperor typically inhabits deciduous and mixed woodlands, particularly those with a presence of sallow (Salix species), which is crucial for the larval stage. It prefers broadleaf forests with plenty of canopy cover, providing a cool and moist microclimate. These areas often have a rich understorey, which helps maintain the humidity levels necessary for its lifecycle.

Apatura iris occupies a unique niche as it spends much of its life high in the tree canopy, descending only to feed on aphid honeydew, tree sap, or to drink from puddles. This behavior reduces competition for resources with other butterfly species. Its dependence on sallow trees for egg-laying and larval development defines its ecological role within these woodland ecosystems. Seasonal variations, such as the availability of sallow leaves and the presence of sunlight for basking, influence its activity patterns and distribution within its habitat.