The generation between the 1789 and 1814 changed a lot of things about France for good. What it didn't do was establish a national consensus about what kind of government was best for France.

First, a brief and oversimplified refresher on the political trajectory of the French Revolution:

• Before 1789, France was an absolute monarchy, with the king possessing both executive and legislative powers (though subject to checks from groups like the parlements)
• From 1789 to 1792, France was a constitutional monarchy, with King Louis XVI sharing power with elected legislators
• In 1792, the First French Republic was declared
• In 1794, Robespierre was executed and (in 1795) different constitution, the Directory, was implemented
• In 1799, the Coup of 18 Brumaire replaced the directory with a government led by three Consuls, in effect a republican dictatorship led by First Consul Napoleon Bonaparte
• In 1804, Napoleon was proclaimed Emperor of the French, returning France to a monarchical form of government (albeit one with very different trappings and organization than the old ancien régime)
• Napoleon abdicated after military defeat in 1814, replaced by King Louis XVIII, younger brother of the guillotined Louis XVI
• Napoleon returned in 1815 for the "Hundred Days," but abdicated again after Waterloo, leading to the Second Restoration and Louis XVIII's return

As I said, that leaves out a lot, but the biggest takeaway should be the sheer multitude of different forms of government that were tried in the 25 years after 1789. France was governed by different forms of republic and different forms of monarchy. All of them had ended in chaos and collapse. People at the time still had preferences for which form of government was best, of course, but there was no consensus.

Now, with that established, you ask: "How on Earth did France return to a monarchy throughout a large section of the 19th century even after the French Revolution?"

The key to that question is that it wasn't really the French who were deciding what form of government France should have. The French armies had been soundly beaten (though not annihilated) and hundreds of thousands of foreign soldiers from Britain, Austria, Russia, Prussia, and a host of smaller states were flooding the country. Any decision about France's form of government was going to have to meet their approach. And all four of these Allied Powers were monarchies of various stripes. So it's not surprising that they were settled on monarchy of some sort as the best government for France — especially since the idea of "republic" largely conjured up images of the Reign of Terror and revolutionary armies surging across Europe. There was zero serious consideration of a return to a republican form of government.

But if France was to have a monarch, what variety of monarch? There were several options.

• The Bonapartist regime could have continued, with Napoleon's young son succeeding him under the regency of Napoleon's wife Marie-Louise. Since Marie-Louise was the daughter of Austrian Emperor Francis II, the Austrians were unsurprisingly the keenest supporters of this idea, but for the same reason none of the other governments liked it very much.
• France could have restored the old Bourbon line of kings, in the person of the self-proclaimed Louis XVIII. We know this is what France ultimately ended up going with, but it was far from a foregone conclusion. Restoring the Bourbons appealed to monarchs who themselves relied on succession by inheritance, but there were concerns about whether Louis XVIII would have any support, and whether he would repeat the same mistakes that had gotten his brother overthrown. The British, who were hosting Louis XVIII in exile, were his most prominent supporters.
• Alternatively, there were several prominent figures out there who could have been crowned king, but who would have represented more modern monarchs than Louis XVIII. The two most important of these were Louis-Philippe, the Duke of Orleans — a cousin of Louis XVIII who was in the line of succession but had a liberal reputation — and Jean Bernadotte, a former Napoleonic marshal who had become King of Sweden. If the Austrians were the biggest supporters of a regency under Marie-Louise, Tsar Alexander of Russia was the biggest exponent of these alternatives — he personally disliked Louis XVIII.

There is a widespread belief — even expressed by some people at the time — that after more than two decades the Bourbons were forgotten in France before the Restoration in 1814. While there's certainly some truth to that — 20 years is a long time, especially in a period with lower literacy and shorter lifespans — this appears to be greatly exaggerated. Even if most people in France got on just fine without ever thinking of the Bourbons, there was a consistent (if often quiescent) royalist minority in the French Empire, and period dispatches and official reports show Louis was taken seriously as a usurper. As Louis XVIII's biographer Philip Mansel writes, "People may not have known the names and relationships of all the Bourbons (did they of the Bonapartes?), but they knew that a brother of Louis XVI, called Louis, was living in exile and had not renounced his claim to the throne."

But not being forgotten is a low bar to clear. As mentioned above, Louis XVIII's claim had two major obstacles: concerns about whether he would have any popular support, and worries that he'd try to restore the old absolute monarchy of pre-revolutionary France — a system of government that almost everyone in the powers-that-be agreed was unsuitable for the present day. The latter Louis addressed in 1813 with his so-called "Hartwell Declaration," where he promised not to turn back the clock too much — he'd retain the administrative changes put in place over the past decade, pursue a policy of peace, and refrain from pursuing retribution against his enemies.

That kept Louis in the game in 1814 as France's armies fell back — an intransigeant dedication to restore the ancien régime in its entirety, as some royalists wanted, might have doomed his claim. But he still needed to show he would have support and not just be a weak foreigner-imposed ruler. As Tsar Alexander wrote in January 14:

The powers will not decide in favor of the Bourbons, but they will leave the initiative on this question to the French... They will not prevent the Bourbons from acting beyond the lines occupied by their troops, but will not encourage them and will avoid even the appearance of taking the least part in their activities.

As an example of this, consider the city of Dijon, occupied by the Austrians, where a group of royalists tried to stage a pro-Bourbon demonstration; the Austrian military governor banned the protest and arrested one of the ringleaders. "Let France speak out," said the Austrian leader Count Metternich. "It's her business, not ours."

The key moment here would come in Bordeaux. One of those armies invading France was the Duke of Wellington's, advancing north from Spain. Wellington personally was favorable to Louis XVIII's cause, but was under the same orders of neutrality as everyone else. He threaded this line by giving these orders to the general he sent to take Bordeaux:

If they ask your consent to proclaim Louis XVIII... reply that wherever our troops are, as long as public peace is not disturbed, we will intervene in no way to stop this party from doing what it considers useful and appropriate to its interests, ... that nevertheless the aim of the Allies in this war is above all else... peace, and that it is well known that they are engaged at this time in negotiating a treaty with Bonaparte [this would come to nothing], and that however disposed I might be to give aid and assistance to whatever group might be opposed to Bonaparte, this assistance would cease at the very instance when peace should be concluded; and I beg the inhabitants to weigh this point carefully before raising the standard of revolt against the Bonaparte government... If the city government claims to proclaim Louis XVIII only by virtue of your orders, you are thereupon to refuse to give them.

Traveling with the English army was Louis's nephew, the Duke of Angoulême, one of several royals dispatched by Louis to different parts of France to try to rally support for his cause. Awaiting them in Bordeaux (which Napoleon's officials abandoned without a fight) was a cabal of royalist activists including the mayor of Bordeaux Jean-Baptiste Lynch, who greeted the British arrival on March 12 with a pro-Bourbon demonstration:

Lynch then jumped up in his open carriage and with a theatrical gesture tore off his tricolored ribbon of office and revealed underneath a white ribbon [the Bourbon emblem]. He then put the white cockade on his hat and shouted "Long live the king! Long live the Bourbons!" The gesture and the shout were imitated by those around him, and the crowd was caught up in the excitement. "There was a roar from what seemed like a tremendous crowd of people, with mingled cries of 'Long live the king!' rending the heavens," one unenthusiastic witness reported.

A few hours later the Duke of Angoulême entered the city to a rapturous reception, and set up a government with support from local elites.

News of this event — suggesting that royalism had a genuine popular base in at least parts of France — spread quickly. When the British prime minister heard the news, he sent immediate instructions off to his negotiators telling them not to sign any deal with Napoleon. (Those negotiations had already collapsed by this point.) Metternich and the Prussian minister on hand agreed to support Louis XVIII.

Continued