A French constitutional monarchy and its competing dynasties

What would happen if France restored a constitutional monarchy, and which dynasty might return?

The proposed route is to replace the presidency with a monarch, with Bourbon and Bonaparte alternatives considered; the wider European Union consequences remain unresolved.

A hypothetical restoration raises two separate questions: which dynasty would return and which part of France's existing political structure a monarch would occupy. The Bourbons and Bonapartes are considered, with Louis Philippe then identified as the historical constitutional-monarchy example. One proposed institutional route is to substitute a king or emperor for the president while retaining the legislature and prime minister. Napoleon III's move from the presidency to imperial rule supplies an analogy, although the hypothetical restoration is framed as constitutional. The opening question about consequences for the European Union is raised without a developed answer.