It is quite often I see Henry VIII described as Henry VII, and vice versa. Heck, when I’m not paying attention and I haven’t yet had my coffee, I’ve been known to do this myself. Don’t let this happen to you! Usually it’s just a nasty typo, but sometimes people do confuse these boys.
You already know this, but to recap:
Henry VII: Father of the Tudor Dynasty (and usurper, to Ricardians), hailed from Wales, reigned from 1485-1509, father of this Henry —>
Henry VIII: Son of Henry VII and Elizabeth of York. Famous for being massive, having 6 wives, having some of them killed, father to other iconic English monarch Elizabeth I, among others.
In short, watch your “I”s!