In Which Emperors Abound:

It's not difficult to find better photos of the Purple Emperor (Apatura iris) than this one. For what it's worth, this is definitely not a White Admiral, because the occasional rapid flyby at head level confirmed that, but the ten specimens we recorded (being conservative to avoid double counting), spent almost all their time courting at the tops of the major Oaks. Also worthy of note: Purple Hairstreak 2; Marbled White 3; Silver-washed Fritillary - too many to count (Extra).