First of all, I think this question is an excellent set up for good, contextual historical analysis of a topic that is woefully misunderstood today. Unfortunately I do not have the background to address the heart of your question, how different were France and the Holy Roman Empire in the 15th century. But I love that question because you have recognized that the way we talk about the Holy Roman Empire feels out of place when comparing it to its contemporaries. And since I am at least somewhat familiar with the modern historiography of the late Holy Roman Empire and Habsburg Empires from studying the Czech lands, my response will primarily be focused on going through some of the ways scholars have begun to rethink the assumptions that produced the historical conundrum you identified.

The modern historiography of the Holy Roman Empire is, to put it bluntly, terrible. It runs afoul of all patterns for writing history based on nation states. To briefly go over the “old” narrative, the Holy Roman Empire in the modern era was a medieval holdover. This relic was doomed to fail because it, and the wider Habsburg Empire, acted as a “prison house of nations” who orchestrated a massive jailbreak at the end of WWI. This story of history as a long march of progress centered on the inevitable rise of nation states is badly suited to understand the Empire. If the Holy Roman Empire was “doomed” to collapse for 400 years, was it really doomed? And national loyalty within the Empire was not even necessarily at odds with the Empire. But comparing the Holy Roman Empire to any nation state is anachronistic and relies on comparing a real, existing government to the state as a theoretical concept.

This is not AskPoliticalScientists so I wont get into the debates about the proper definition of a state (this post was made by a Charles Tilly supremacist), but just keep in mind that there are various definitions of states. By almost all definitions, they did not exist before the 16th-17th centuries, with some rare exceptions. And a world system made entirely of states is a very modern phenomenon. Since a state is a theoretical concept, it is also worth considering how many states exist in the real world today that completely fit the ideal model of a state? An ideal state is usually centralized. But how many polities that we readily accept as states have decentralized administrations? States are defined by sovereignty over their borders and possessing the monopoly on violence. But how many states have full sovereignty over their borders and an absolute monopoly on violence within their borders? I’d argue that many of the political structures which we unquestioningly refer to as states do not fit neatly into this mold. So from the beginning we should avoid comparing the Holy Roman and Habsburg Empires to a state. Instead, we should consider it as a political organization determined by the evolution of its own unique historical context.

I think the best way to start understanding the Holy Roman and Habsburg Empires is as a network of localized histories. This collection of different histories makes it difficult to form a single, unified narrative of what this thing was. The Empire was not the “prisonhouse of nations” and it did have a degree of cultural hybridity, but it was no multicultural paradise either. It was a “Christian” empire, but it was not a proselytizing one. A central administration began to emerge in the 15th century under Emperor Sigismund’s rule but there was still not a central policy. After the 30 Years War, it became a sort of federation with the Emperor acting as supreme arbiter. By the 18th century, the titles and iconography of the Empire had become archaic, but the government as it was actually practiced was not. Instead, local policy was used and resolved by a traveling universal court. I could go on, but the point is that it is very difficult to come up with one narrative from all this.

The power that the Holy Roman Empire had was not in territory, like it was for the Anglo-French model of early modern polities. The HRE’s power was in networking, not nations. A mobile, cosmopolitan, cultural elite who operated beyond modern state-centric understanding of space, travel, power, etc. cannot be understood on those terms. And this power was crucial to the history of the later medieval/early modern period (roughly post 1550). It is easy to ignore the old history because it just doesn’t make sense to use, but the HRE’s early contract laws and federalized court system in the 16th century arguably lays some of the foundations for the modern world. My first Habsburg studies professor argued that this was the beginning of the bureaucratization of Europe. She suggested that abstracting power instead of personalizing it like the absolute monarchies did in places like France, local power can arise without singular authority and produce a more fluid and localized polity that is still durable. And the emperor who upholds the governing myth can be called up to fix things as needed.

To summarize, I want to suggest that in the early modern period the Holy Roman Empire was not based in a physical space like a London or a Paris. Power and borders were based on large networks and contractual agreements that resisted centralization. To be clear, I am only talking about the Holy Roman Empire from the 16th century onward. But in the early modern era, the Empire did not rule by force because it was not looking to rule by force. Perhaps we could look at it as almost a coalition of regional groups with common interests. In a way, it was the most modern European government of its time.

So I recognize that this has been me going quite hard in the opposite direction to make a point. That point is that we really need to reevaluate the way we talk about the Habsburg Empire. I know I brushed over a lot of this and it really didn’t address the heart of your question, so I’ll try to clarify anything that needs it. And hopefully someone else with more of a background in late medieval French or Spanish history can chime in to draw the comparison you were looking to get.

Three big books on this topic worth mentioning:

AJP Taylor, The Habsburg Monarchy, 1809-1918, 1948.

>This was the standard narrative of Austria-Hungary for decades. It is classic 20th century Oxford-educated history. Taylor presents an Empire that is entirely determined by its foreign relations. It has no agency in its own history. Napoleon made it, Bismark reformed it, WWI killed it. This is an outdated book, but an interesting one for people looking to get into the weeds on this. He does have an amusing argument about how Czechoslovakia and Yugoslavia were the successor states that inherited Austria-Hungary's problems because they were multiethnic. At one point he says that Czechoslovakia raised the question "what if Austria-Hungary was democratic?" and answered it with a solid "nope."

Robert Kann, A History of the Habsburg Empire, 1526-1918, 1974.

>Kann addresses some of the major problems with Taylor's work, but it suffers a bit from the second opinion bias to be as much of a contrarian as possible. For example, Taylor divides the Holy Roman Empire from the Habsburg Empire, so Kann argues that the Habsburg Empire existed in fact before 1804 even if it was not in name. And this is cool. But then he goes all in and argues that the Habsburg Empire started precisely in 1526 after the Battle of Mohács, but he doesn't really explain why this particular territorial acquisition was the turning point. His best improvement on Taylor imo is recognizing the Habsburg Empire had long-term cultural significance. But he also argues the empire was in steady decline from 1815-1918 which feels like it glosses over a lot of nuance.

Steven Beller, A Concise History of Austria, 2006.

>Beller’s ironically named Concise History of Austria is a brick and I really do not recommend trying to get through the whole book. He covers everything from prehistory to the year he published this thing. But he does some cool stuff with periodizing the Habsburgs into three eras that covers a lot of the Holy Roman Empire proper; AEIOU 1439-1741, Countering Reform 1740-1860, and Empire on Notice 1866-1918. He does the best out of the three by saying the empire declined for only 50 years instead of several centuries, so that’s cool. His general framing of Austrian history as “the history of the other side of Europe” is provocative and fun to play with.

Sources directly used:

Chad Bryant, “Habsburg History, Eastern European History … Central European History?” in Central European History vol. 51, no. 1 (2018).

>This article has a good overview of relatively recent literature for those who want to read more.

Martyn Rady, The Habsburg Empire: A Very Short Introduction, 2017.

Joachim Whaley, The Holy Roman Empire: A Very Short Introduction, 2018.

EDIT: There seems to be some confusion about how I am using the term "state". Perhaps I assumed too much familiarity with how English-language political science talks about state theory. "State" is commonly used as shorthand to refer to the modern sovereign state model that emerged in Europe after the Treaties of Augsburg and Westphalia. I suggest checking out the excellent comment below by u/Lord_Cangrand. And for some of the theoretical background, Charles Tilly and Max Weber's definitons of modern states are both good place to start and widely known in the field.