https://en.wikipedia.org/wiki/Order_of_the_Garter
https://en.wikipedia.org/wiki/List_of_current_Knights_and_Ladies_of_the_Garter

https://en.wikipedia.org/wiki/House_of_Oldenburg
Cadet branches:
Augustenburg (extinct)
Glücksburg
Holstein-Gottorp
Romanov line
Swedish line (extinct)
Grand ducal line

ALL THESE LINES ARE CONNECTED TOGETHER! IT'S NOT A THEORY IT'S A FACT. Every road you go, you go back to these "royal" families.

https://en.wikipedia.org/wiki/House_of_Palatinate-Simmern (German Bavarian-connected to Windsor)

https://en.wikipedia.org/wiki/House_of_Welf