Franco British union
The union of two countries
The British and the French would talk of the Union even after the war and after the war, Elizabeth II her self should not marry a german, she is engaged to Prince Philip and the engagement was cancelled by the parliament on 1946 and chose another man who would marry her.
Winston Churchil and De Gaulle would decide that it is best not to marry Elizabeth II to a german or the union would not happen and instead they chose Alfonso, Duke of Cadiz and Anjou as her prospective husband who would be crowned as the Titular King of France in order for the wedding to push through.
Elizabeth herself would be okay as she would be under the rule of the parliament, the condition for the marriage would be that Alfonso, duke of Cadiz and Anjou would renounce his claims to Spain and convert to Anglicanism, the wedding would happen on January 10, 1950, she would be in charge more of the image of the two countries while her new husband,Alphonse II of France would be there in order to support her duties, after the marriage on February, the union of two countries was begun.
Note
If we have The Crown in this TL I imagine we would have Ryan Gosling to play as Alphonse II of France..in other movies, Alphonse II is played by Alec Baldwin.
The late Alphonse II of France