2016 Defender won't start - immobilised?

[Straight6DOHC]

Vehicle hadn't been started in around 2 months. It wouldn't unlock with fob. Once inside, it wouldn't crank, in face, turning ignition key did absolutely nothing. No lights on dash, no clicks, nothing.

I removed battery (correct ignition key sequence) and charged 6 month old battery overnight.
Next day, installed battery and again, absolutely nothing upon turning key.

Can anyone advise?

[deja.vu]

You’re far better off posting on one of the Defender face book groups

[blueST]

You’d get a lot of constructive help on defender2.net as well.

[595Heaven]

Have you changed the battery in the key fob?

[LooneyTunes]

Are you sure the battery held charge? Some don’t like being very deep discharged.

I’d be tempted to try jumping it off another vehicle if possible.