In a nutshell, Brutus, Caesar's best friend, approaches Caesar at the Senate and after a few words with him, stabs him. Once Brutus stabs him then everyone else joins in and the deed is done. With his dying breath he can't believe that Brutus has betrayed him like this. Then, Brutus realizes that he's been a puppet of the other sentaors and has plunged his country into a civil war and he takes his own life by 'falling' on his sword.
