Napoleon's Marshals - Boney's Boys in Spain Part 2

Regarding the titles of Napoleon's relatives when in France, I would not know anything about that, and actually, I doubt it. When Joseph, Jerome and Katharina are in France in 1813/4, they are still referred to as kings. When Eugène is in Paris for the baptism of the Roi de Rome, he's still called the Viceroy, and Caroline is being called Queen of Naples throughout the long time she stays in Paris then. Is there a certain incident you are thinking of?

But I have no doubt that between 1804 and 1807, after Tilsit at the latest, Napoleon's plans had changed completely. By 1805, people could still discuss and talk about the future of the country and its place within Europe with him. During the Austerlitz campaign Talleyrand, for example, voted for another marriage option (either for Eugène, or for Napoleon himself after a divorce): not with Bavaria, but with Austria (and such a marriage was indeed offered). This would have secured France's eastern borders long-term (but of course also limited them), it would have secured the Kingdom of Italy, it would have been an option for a lasting peace and for the two empires co-existing next to each other. Napoleon listened, but eventually decided against it, and it's actually unclear if he already had future plans for conquest or if he just distrusted the Austrians so much. Probably a mixture of both. Bavaria just seemed like the easier option.

I feel like the war of 1806 against Prussia was not something Napoleon had planned or expected, and surely not something he had wanted. He may actually have been a bit scared of Prussia's military reputation. And some of the contempt he later showed towards Friedrich Wilhelm may actually be in connection with that. He had treated Prussia like a partner, had almost courted her all those years because he thought she was strong. And then the Prussians showed themselves to be pushovers (or at least that was the common perception). During the campaign in Poland, in May 1807, died the oldest son of Hortense and Louis Bonaparte, whom many had seen as a future heir of France. Finally, at Tilsit Napoleon and Alexander basically split up Europe between themselves, and this is also the time when Josephine's repudiation was fixed. (If it had not been decided already before. It is to be noted that Napoleon already had to defend his decision to have Josephine crowned and to keep her around as empress in 1803/4. And the Austrian ambassador wrote to Vienna in 1804 that there were rumours Napoleon would divorce Josephine and marry - the oldest daughter of the Bavarian elector Max Joseph...)

I think, before Tilsit, Napoleon really "only" wanted a strong France with a couple of obedient vassal states, Holland, Kingdom of Italy, Naples, Rhinebund. New conquests were added to one of those states usually (like Venice to the Kingdom of Italy). After Tilsit, this changes completely. Newly acquired territories now become French departements (Illyrian provinces, Rome). Napoleon repeatedly changes the borders of the states he had created (Holland and Westphalia), going as far as to annex the kingdom of Holland when Louis abdicated 1810, thus depriving his own nephew of a throne. Murat, by 1808 king of Naples, was repeatedly threatened with the same fate basically from the moment he took to the throne, and I have found similar threats, though better veiled, in Eugène's correspondence.

So, in my opinion, even before the King of Rome was born, Napoleon had decided on a large territorial state and an empire under his direct rule (that he had not planned to have originally). Eugène would never receive the kingdom of Italy. Joseph, sitting on the throne of Spain (more or less) had no sons. Jerome in Westphalia also had no son at the time, though I'm not sure how interested Napoleon was to acquire that region. Tuscany was ruled by Elisa, who had only a daughter, I believe. And finally, Naples. Where Murat had no less than two sons. But those would not inherit. When Napoleon gave the kingdom of Naples to him, he stipulated that the first heir would not be the oldest son Achille. But Napoleon's sister Caroline. Keeping the kingdom safely within the Bonaparte family, and within Napoleon's direct reach.

Let's just say, I see a lot of options there.