Upvote:1
A foreigner as a ruler is (or perhaps was) quite common in Europe. Many European emerging nations looked for (usually) German princes when they gained their independence, if they wanted to become a kingdom and didn't have a royal family. The supplying royal families found this an excellent way to employ their sons not in line for the throne.
Why German princes? Because Germany had many, very many, princedoms and smaller kingdoms.
The Belgian kings descent from a German prince. So does the Dutch royal family, be it by now very indirect. The direct bloodline died out a couple of times. That Dutch royal family briefly occupied the throne of England, under William III.
To be precise, William I of Orange was a French, not a German prince. Originally he was heir to the county of Nassau, before he inherited the French principality of Orange. There is much more to that, but that is outside the scope of this question.
The British royal family changed their name from Saxe-Coburg-Gotha into Windsor during WW1 for obvious reasons. The Saxe-Coburg-Gotha family was a German royal family.
George I of Greece was a Danish prince. Ferdinand I of Bulgaria was a German prince. Czar Ferdinand I of Bulgaria was also a German prince.
Upvote:2
Historically, this is not a "curious fact" but rather a general rule. I mean the time when "national leaders" in Europe were monarchs. It is very common for a monarch to be a foreigner.
Some examples: William I and William III of England, and their descendants, Romanov's dynasty in Russia after Peter I was mostly German. And most other European monarchs.