If it were me teaching my kid:
1.) Describe the fall of the fall of the Western RE, in general terms. And the surviving ERE.
2.) Rise of the Franks -- a Germanic people. Karl/Charlemagne's ancestors actually built most of the
Carolingian Empire, he just put on the finishing touches.
3.) Family drama with Karl's brother, and his mysterious death. Mommy is suspect. Karl thus inherit's Pepin the short's former realm.
4.) Briefly describe the Germanic Lombard invasion of Italy. 2 Germanic kingdoms, w/ Muslim invaders creeping in from the south. Alliance seems like a good idea.
5.) ^This was to be achieved by Karl marrying a Lombard princess.
6.) Marriage didn't work out, and she fled back to Italy. But, treacherously, she took one of the young Karling pretenders with her. So what are they planning to do? Plot to take Karl down, from beyond his borders? Obviously this can't be tolerated. Invade Lombardy.
7.) Bishop of Rome, now calling himself the Pope (a king-tier title), and seeking to egregiously extort all of western Europe for many centuries, is spooked by Karl's rapid expansion & the fact that he's now on the Pope's doorstep.
8.) Seeking personal gain (lands in Italy) and making Karl morally unable to do anything but be magnanimous to the Pope, Bishop of Rome goes for max flattery by declaring Karl emperor of the Romans. This was made easier by the fact that the ERE was ruled by a woman at the time (title was considered vacant, according to them in the west).
9.) Ploy actually works, and the Germanic Franks actually start to believe that they are 'Latin' over time. The 'new emperors of Rome', as it were.
10.) Karl dies, his realm splits.
11.) His heirs die, more realm splitting.
12.) West of the Rhine (areas that actually were conquered by Rome), they're really taking this "we're the Romans" thing seriously. Next ting you know, they're taking vulgar Latin, and forming a new bastardized version of it, and it sounds absolutely silly.
13.) East of the Rhine, where they were not conquered by the Romans, no such silliness is being entertained. "We're German, and we're proud of it".
14.) ~200 years after Karl's preposterous receiving of fellatio crowning, new consolidation efforts are sought to reunite realms, along the cultural lines that have evolved since his time.
15.) Now that the Pope is fully embedded throughout all the realms of western Europe, and his cult is in total psychological control of everyone, the only way to really do this, is in concert/cooperation with him, the Pope.
16.) German kings manage to fight for about this much territory (show map of ca. 1000 A.D. HRE), destroy the kingdom of Burgundy once and for all, crusade a little into the Slavic lands to the E and NE (forceful missionary work, you might say). And w/ Papal collusion, they divided Italy among themselves.
17.) Over time, Pope wants even more of Italy, and this led to funny things like HREmperor being excommunicated, having to kneel in a blizzard for days, etc.
18.) As for the core realms, along w/ the peripheral realms of the HRE, the Reich is just too culturally diverse to be fully centralized. So explain that the HRE is really more of a confederation under an over-arching crown, than a 'nation state'.
19.) Over time, the non-Germans would be shed from the empire. As this occurred, centralization was therefore gradually able to increase. Austria (Habsburgs) becomes the driving force for a more centralized 'Grossdeutschland'... a state of all ethnic Germans, unified & centralized.
20.) Austria was Germany before Germany was Germany. Modern Germans know this, and pay tribute to Austria by their selection of the tune for their national anthem.
21.) Prussia begins to rise (another topic/lesson perhaps), and has other plans.
22.) French revolution, and then later Napoleon begins to rise. He also, has other plans.
23.) Austria/HRE crushed, and it's dismantled. Now all the German minor states are up for grabs. The game's afoot; who's finally going to create a German nation state?
24.) Spoiler; it was Prussia. Of course, Prussia was really Brandenburg. Brandenburg... re-branded. Because when you're a margraviate (glorified sheriff) that was usually a vassal of Bohemia, and given electorate status just to vote for Bohemia, and you're always remembered as the 'sandbox' of the HRE, a den of bandits & robber knights, yeah it's best to get a PR makeover. How about the legendary, fabled Teutonic knights? (New) "Prussians". Absolutely, that's who they are now. But give them credit, they built one hell of a military tradition, which is how they managed to actually pull it all off by 1871.
25.) Everybody joins the new Germany, except Austria... which still had plenty of other realms which were not ethnic German.
26.) After WWI, A-H gets broken apart, so how they're on their own (the former core realms of the Habpbpbsburgs). Well, unless you wanna hear about WWII, I guess. But that's enough lesson for one day, son. Go do your chores, and then we'll hit the gym. We don't have to worry about any of this old-world crap anyway, you know. There's reasons we left in the first place. But at least now you begin to understand.
