Here's a fun what-if I stumbled upon while browsing Wikipedia. Turns out thatJaime, Duke of Madrid was the Legitimist pretender to France
and the Carlist pretender to Spain in the early 20th century.
The POD: the Spartacists take over Germany in 1919. This creates an extreme phobia of the left in France. After a worse Depression hits, a reactionary monarchist coalition takes power in France (ALA Mussolini) with Jamie as its leader. In the late 1920s Jamie becomes King Jacques I of France. He survives past 1931 due to living in better conditions in France.
Then in Spain, the Second Republic is established and Alfonso XIII is executed before he can flee. His sons are forced to flee and renounce all rights to spain. The Spanish Civil War takes on a different character, with French intervention on the side of the Nationalists.
The Nationalists win the civil war and drive out the republicans. The need a new king, and first in line is Duke Jamie of Spain. He is crowned in Madrid in 1941, and thus has become king of both France and Spain.

What do you think? Totally ASB, I know, but it was fun writing it.
