In 1905 Norway became independent of Sweden. They thought of several European to whom they could offer the throne but their chosen candidate was Prince Carl of Denmark.
What if they had chosen someone else or Carl had turned the offer down??
Something of a precedent had been established by the former Prince of Denmark, regent in Norway 1814 Christian Frederick, later Christian 8 of Denmark was elected King by the Norwegians 1814 and kept the crown until giving in to Sweden.
turned down the offer - never:
Carls father Frederick the 8 was the brother of Alexandra married to Edward 7 of Britain, brother of Vilhelm king of the Hellenes as Georg 1, brother of Dagmar married to Tsar Alexander 3 of Russia...
Someone else - someone in protestant Germany I guess.