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As it says on the tin: Napoléon's stepson Eugène de Beauharnais had two sons of his own, Auguste and Maximilien. Auguste was at one point in the 1830 Revolution considered for king of the Belgians, and although this didn't happen, four years later, he married the young queen of Portugal, D. Maria II. His brother, Maximilien, married a Russian grand duchess (despite his mother (a Princess of Bavaria)'s entreaties not to, out of fears that the Beauharnaises would become Russified and, worse still, to her Catholic eyes, Orthodox), and the Beauharnais did reasonably well at the Russian court until the Revolution.

However, the line of the Empress Joséphine through which most modern royals descend from her, is through Eugène's eldest daughter and her namesake, who married the likewise parvenu Bernadotte crown prince of Sweden.

So, what would Europe look like if we got a Beauharnais (instead of a Coburg) Belgium/Portugal? I assume Auguste wouldn't be eligible to marry D. Maria II, so the empress might promote her younger brother instead. Where might Auguste marry? And how would Europe react to a remnant of Imperial France getting a throne? Sure, they liked the Beauharnais much more than the Bonapartes (although that might've been because of Joséphine's personality and Eugène's marital connections), but let's be serious, would he be in the same parvenu boat as the Bernadottes for a while?
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