I .. uh .. what?
What sort of political LUNACY would there need to be for that to happen?
I mean, Kingdom of Jerusalem being made is difficult at best.
You'd need some serious political jiggery-pokery to make England a HRE member, as it become one of the largest.
And... If Henry the Lionhearted is EXECUTED?!
AHC? More the AHC-Beyond-Belief.
All I can consider is maybe a Kingdom of Jerusalem is created as a HRE vassal. John tries to usurp england with Frederiks help in exchange for becoming a vassal - and then Richard (still in the Levant) tries to overthrow whomever is the King of Jerusalem, fails, it captured, and then executed after... excommunication by the Pope?
Seriously mental times to pull that off. Perhaps have john actively 'support' his brother by sending Richards supporters to the holy land so he has dominance - a easier PoD - but eeps