I should also add my apologies, for extending the discussion to any who’ve been bored as well.
I think counterfactual history is actually quite a Fortean topic making us realise what huge consequences a relatively minor issue can have.
What Tyler you are right the whole business of Edgar Atheling is a huge unknown. There doesn’t seem to be much known about his character or abilities. If he hadn’t manage to repel Hardrada would that have given William the excuse he needed to launch his invasion, thus “pinging” history back to something close to what we have today?
Alternatively if Hardrada had defeated Harold he would still have William to deal with. As you say he wouldn’t have been bothered about what the Pope, or anyone else had to say but he could still have lost. A different Harald being beaten by William in a different battle but again with a result close to what we have today.
If Hardrada had defeated them both then we would have been an essentially Danish Kingdom. I suspect that Tostig would have suffered an “accident” (falling backwards onto seven or eight swords or some such).
It almost seems as if fate was on William’s side. His “disaster” when his fleet was caught in a storm in early September on his first attempted crossing actually working in his favour, as if he had made it then Harold would have been waiting.
The whole business of a crossing in October is a piece of luck as well, most people would have ruled it out because of the weather, (just think of the problems the weather posed in 1944) but if William had delayed six months Harold would have been more prepared.
Edward should have nominated an heir to the assembled Witan, perhaps he didn’t because, well, “accidents” happen?
(Almost) Back to topic, it seems that William was deliberately “harrying” the south on his arrival, perhaps to provoke Harold – once he knew him to be the victor at Stamford Bridge- as Wessex was his old earldom, to get him to rush to its defence. A more cautious but perhaps less popular course of action would be to send one or both of his brothers to harass William while he collected his forces. (As What Tyler said, Gyrth offered) It seems William had gambolled everything and would have had trouble getting his forces back to Normandy in the event of defeat. That could have been a way of subverting the Breton allies if the campaign started to look doubtful (Give us William and Odo etc. and we’ll give the rest of you boats home)