Who do you think is or was the biggest genius to have ever existed? He/She can be from any time-period, from the past or the present day. Can be anyone that you think deserves the title "Historys Bigges Genius".
I am going to say 19th centurys Benjamin Barker. XD
His talents as a barber helped pose him and keep him in the shadows as he took revenge on the people whom ruined his life, and also invented an awesome chair to dispose of the bodies of the people that he killed through a shoot in the ground to the kiln where they were roasted and then turned to pies.
That is just genius classic evil mass murder style that helped him go down in history as one of Londons most successful and popular anti-heroes. Haha.