Why was Cesare Borgia so feared?

Why was Cesare Borgia so feared? ♦Consider to Support the Channel of Patreon and gain cool stuff: https://www.patreon.com/Knowledgia ♦Please consider to SUBSCRIBE : https://goo.gl/YJNqek ♦Music by Epidemic Sound ♦Sources : Niccolo Machiavelli - The Prince Paul Oppenheimer - Machiavelli: A Life beyond Ideology Paul Strathern - The Artist, the Philosopher, and the Warrior: Da Vinci, Machiavelli and Borgia and the World They Shaped Sarah Bradford - Cesare Borgia: His Life & Times ♦Script & Research : Skylar Gordon #History #Documentary #Borgia