https://en.wikipedia.org/wiki/Infanta_Ant%C3%B3nia_of_Portugal and her husband brother of the castle owners.. https://en.wikipedia.org/wiki/Leopold,_Prince_of_Hohenzollern had also children of course one of them was "Prince Ferdinand of Hohenzollern (25 August 1865 – 20 July 1927) he married Princess Marie of Edinburgh on 10 January 1893. They have six children."
So https://en.wikipedia.org/wiki/Ferdinand_I_of_Romania married
https://en.wikipedia.org/wiki/Marie_of_Romania (Marie of Edinburgh) one of them children was daughter https://en.wikipedia.org/wiki/Elisabeth_of_Romania who then married https://en.wikipedia.org/wiki/George_II_of_Greece , who is paternal first cousin of Prince Philip, Duke of Edinburgh, and a maternal nephew of Wilhelm II, the last German Emperor.
AND GUESS WHO MARIE OF ROMANIA/EDINBURGH IS "Born into the British royal family, she was titled Princess Marie of Edinburgh at birth. Her parents were Prince Alfred, Duke of Edinburgh (later Duke of Saxe-Coburg and Gotha) and Grand Duchess Maria Alexandrovna of Russia."
https://en.wikipedia.org/wiki/Grand_Duchess_Maria_Alexandrovna_of_Russia you already know which family is connected to them.. her father is https://en.wikipedia.org/wiki/Alexander_II_of_Russia
so who's prince Albert? oh "He was the second son and fourth child of Queen Victoria of the United Kingdom and Prince Albert of Saxe-Coburg and Gotha."
all roads leads to where...?