Question: Prince Nicholas of Greece and Denmark was the son of which king that was assassinated in 1913?  
Sentence (from "George I of Greece"): George I (Greek: Γεώργιος Α΄ , "Geórgios I"; born Prince William of Schleswig-Holstein-Sonderburg-Glücksburg; 24 December 1845 – 18 March 1913) was King of Greece from 1863 until his assassination in 1913.
Relevant evidence: Yes