If Henry VIII's older brother Arthur hadn't died before he could claim the throne, would he have been known as Arthur II?

by TheyLaughedAtMyPenis
Gadarn

No. The monarchy of the Kingdom of England only goes back to Alfred the Great (and even that's only by tradition - Alfred never called himself the King of England).

'King Arthur' (if he existed) lived around 400 years before that, likely wasn't a king, and definitely wasn't English.

That said, the name was specifically chosen to connect the Tudors with King Arthur and to hearken back to a golden age.