I think this is a male. I spotted it in flight and initially took it for a female - no visible hint of gleaming blue during the brief time it twisted and glided in front of me - but from its general appearance and the way it then sat high in the sallow for the next hour, I changed my mind to male. Some shots taken when it opened its wings showed a very, very slight note of purple:
According to MétéoSuisse - and matching my own observations - this autumn is falling a couple of weeks earlier than average, measured by phenological indicators like hazel catkins. His Imperial Majesty truly is a law unto Himself!
Will this be the last record from the Empire this year?