Queen Victoria Eugenia of Spain , Crown Princess Margaret of Sweden , Crown Princess Marie of Romania , Crown Princess Sophia of Greece , and Empress Alexandra of Russia were his nieces ; Haakon VII of Norway was both his nephew by marriage and his son-in-law ; Frederick VIII of Denmark and George I of Greece were his brothers-in-law ; Albert I of Belgium , Ferdinand of Bulgaria , and Charles I and Manuel II of Portugal were his second cousins .