I know that the history of the Holy Roman Empire is, shall we say, complicated.
But for a while now I've been puzzled about how maps of the Empire are portrayed.
Generally most of Northern Italy (not including Venetian holdings or the Papal States) is shown as part of the HRE from the Medieval period. But round about the Peace of Westphalia, modern maps of the Holy Roman Empire no longer include any Italian areas as part of the Empire.
Did the Peace of 1648 mark some sort of clear southern imperial boundaries? My understanding is that the Netherlands and Switzerland were no longer considered part of the Empire from this point on - did something similar hold true for places like Milan and Savoy?
/u/Kochevnik81
Great question, this is a rarely-discussed question about the HRE: what about those areas south of the Alps, namely in Italy?
The degree of Imperial control in Italy was long in decline, in particular we should look at the situation in at the time of Maximilian I's Reichsreform in 1495, one outcome of which was the Imperial circles or kreis system. The circles were administrative groupings to facilitate common defense and collection of imperial taxes.
Due to the lack of Imperial control in Italy, theoretical HRE fiefs there were left un-encircled, giving de factor recognition that there was no executive HRE power there. Not that they didn't pay their dues at all. They did, for example, pay for 0.7% of the war funding to support the Long Turkish war all through 1709. But even in the days of Maximilian I there was already a losing battle to re-assert HRE authority in Italy. One one hand, his grandson Charles V was able to enfief Milan onto his personal domain, yet he and his successors kept Milan out of HRE influence, especially after the Habsburg inheritance was split between Philip II (who retained Spain and Milan and the Low Countries and their appendages) and Maximilian II (who retained Austria and Hungary, in addition to HRE emperorship).
So it was not the Peace of Westphalia in 1648 that marked the Italian territories as separate from the HRE, rather earlier trends with two major milestones, namely the Imperial Reform of 1495 and Charles V's annexation of Milan.
Finally, speaking of Westphalia, you may want to read through what more precisely was covered, and not, in that agreement.