How many heads of state were assassinated in the past?
https://en.wikipedia.org/wiki/Category:Assassinated_heads_of_state
I don't feel like spending the time to research a more complete list, so here's the Wiki version. You can do more in depth research yourself if you like, though why bother?
Though I will add. . .even Stalin was poisoned. Just found that out, and that's what prompted this post.