Thanks for the comment @ozzy158. Indeed, getting away from light pollution is key to getting these types of photos. I'm usually at least 50km away from the nearest town when out on an astrophotography journey, and even then, a faint glow is sometimes visible on the horizon.
I posted a few extra photos a week ago, take a look here if you'd like to see some more: https://steemit.com/photography/@garethb/astrophotography-volume-one-all-original-work