regicide
intentional killing of a monarch
Nepalese royal massacre
event on 1 June 2001 in Kathmandu, Nepal in which Crown Prince Dipendra killed most of the royal family (including King Birendra and himself) with a gun
Assassination of George I of Greece
1913 murder of King of Greece
Lisbon Regicide
February 1908 murder on the king and crown prince of Portugal
execution of the Romanov family
1918 murder of Nicholas II of Russia and his family