As John Wilkes Booth fired the shot that killed President Lincoln, he is reported to have shouted “sic semper tyrannis”. This Latin phrase, meaning “thus always to tyrants”, is sometimes attributed to Brutus at the scene of Julius Caesar’s assassination (although the evidence for this is scant).
Whatever its origins, the phrase is now a rallying cry against abuses of executive power and is codified in the impeachment provisions of the US Constitution. One of its authors, Benjamin Franklin, argued that impeachment was necessary as a judicial alternative to assassination:
“History furnishes one example only of a first magistrate being formally brought to public justice [the trial and execution of Charles I]. What was the practice before this in cases where the chief magistrate rendered himself obnoxious? Why recourse was had to assassinations in which he was not only deprived of his life but of the opportunity of vindicating his character.”
Franklin was almost certainly referring here to the assassination of Julius Caesar as well as any number of other tyrannicides throughout human history (and, prophetically, to the death of Lincoln).
Now, thanks to the research of Dr Jill Pruetz and her team at Iowa State University, it appears that other primates share the human concept of sic semper tyrannis. Her team observed the exile and subsequent murder (five years later) of an alpha male chimpanzee in Senegal. He was despised, overthrown and murdered because of his dominant, abusive behaviour, which led to one researcher nicknaming him Saddam. When he tried to return to the group from exile, a group of younger males attacked and killed him. Even after his death, the assassins feared the murdered ape and abused and cannibalised its corpse.
To my mind, this research provides us with a fascinating insight into our own history of tyrannicide and proves the maxim of sic semper tyrannis (human or chimpanzee!)
(Further details of Dr Pruetz’s research here: http://www.news.iastate.edu/news/2017/01/31/chimpaggression )