It wasn't what happened.Well, Charlemagne looked at the Eastern Empire and decided he could have one too.
Why? If this title was so void, what would have been the interest? Louis XIV was a pragmatic and rather than void titles, he preferred actual territories.It would be theoretically possible for Louis XIV to use a similar justification, that the Holy Roman Empire is neither holy, nor Roman, nor much of an empire outside of Austria, and decide he too can refound the Roman empire.
These states are nevertheless on Spanish and Austrian influence, and any tentative to get one would lead to the immediate war with half of Europe.By this time the Italian territories are outside of the Empire, so there would be no territorial overlap.
It wasn't what happened.
In fact the whole coronation upset Charlemagne a lot. Being emperor meant the Pope sanctioned his reign while he would have wanted to sanction Pope's domination.
Not that he didn't wanted an imperial title, but maybe not Emperor of the Romans.
It was reported he left the basilica in great fury against this.
Why? If this title was so void, what would have been the interest? Louis XIV was a pragmatic and rather than void titles, he preferred actual territories.
Besides, the dominant ideology in France at this time was already a semi-nationalist one, praising classical style, french art, etc. Claiming refounding the HRE would have been counter-intuitive with that.
It was for the trial of the pope Leo III that was rejected by roman nobles and part of the clergy. He went to say "I'm King of Lombards, Patrice of Romans. Stop this shit, and accept my decision on who have to be pope".Interesting; then why did he go to Rome in the first place? I thought he was actually submitting himself to the Pope.
My recollection is he wanted to be emperor, but he didnt want from the popes hands.
He didn't wanted that of an imperial title, at the point he didn't planned to transmit it to one of his heirs.
He knew that he would became emperor and accepted it but he did under the pressure of the elites he protected and/or renewed. Certainly, he had a reluctance to be crowned, whatever the way.
What really pissed him was the fact he was crowned byzantine-way and not frankish-way (well mix of visigothic and frankish way). And by the pope : that meant he didn't had his power from his arms or his position, but under the church's decision.
Finally, things prooved his fears was quite accurate, as the depositary of legitimacy wasn't first the line and prestige, but the Church during all the Middle-Ages.