[Pilsner]

France would have become a monarchy again after its defeat in the Franco-Prussian War had the then pretender been willing to accept the tricolor

France held a sort of constitutional convention and the vast majority of delegates were monarchists. The monarchists could not however decide whether to have a Bourbon, Orleanist or Bonapartist King. All three groups compromised on having a Republic, each calculating that they would pull a coup in few years and place their candicate on the throne. No group ever quite got around to pulling a coup and the Third Republic tottered on until Hitler put it to bed in 1940.

[CatoRenasci]

It's been 30+ years since I did 19th c. French history, but IIRC, the convention was prepared to agree on either the Bourbon or Orleanist pretender. (The bonapartists were never in serious contention) However, as the negotiations proceeded, said pretender would not accept the tricolor, insisting on the fleur d'lis flag (so maybe it was the Bourbon), the bonapartists and republicans in the convention were not willing to give up the tricolor, and so the resulting compromise was the Third Republic. And, as you say, each group figured it could undermine the Republic (which they did, but unsucessfully) as it nurtured a chance at revanche against the pefidious Prussians for marching up the Champs d'Elysee and putting the soon-to-be Kaiser Wilhem I up at Versailles.

[CatoRenasci]

From historychannel.com,

But for the intransigence of Henri, comte de Chambord (the legitimist pretender), France might again have become a monarchy.

Source: The Expanded Columbia Electronic Encyclopedia Copyright© 2003. Columbia University Press.

[CatoRenasci]

Further from the same source:

Chambord, Henri Charles Ferdinand Marie Dieudonne, comte de, 1820-83......In 1871, after the fall of the Second Empire, Chambord's prospects improved, and in 1873 the Orleanist pretender relinquished his claims in Chambord's favor. However, his stubborn adherence to the Bourbon flag in preference to the national flag, destroyed his chance of recognition. He died without issue, and his claims passed to the house of Bourbon-Orleans.

It's really hard to be sympathetic with these bozos....

[aristeides]

No group ever quite got around to pulling a coup and the Third Republic tottered on until Hitler put it to bed in 1940.

Isn't it strange that in 1940, nobody, as far as I know -- not Pétain, not Laval, not even the crazies on the fringes of Vichy -- thought of restoring the monarchy? For all Vichy's talk about a "National Revolution."

DeGaulle came from a Catholic monarchist family. I wonder why he didn't attempt something along those lines. (Well, in a sense he made himself king.)