Julius Caesar was the ruler of ancient Rome, he was great in war and many other things. These facts had made the conspirators jealous; especially Cassius, who wanted Caesar dead. Hence, he had made a plan to kill Caesar but to complete this he needed Brutus.
Cassius had been trying to bribe Brutus, and Brutus has had eternal conflict with himself; deciding whether or not to kill Caesar.
Brutus had decided to agree with Cassius' plan and they had lured Caesar to his inevitable death.
At the funeral of Caesar, Brutus had explained why Caesar had to die. Antony had spoke at the funeral too, but he had spoke what he thought about Brutus and Caesar's death. This had cause Rome to be in an outrage and had been causing Rome to fall.
With Caesars' death, there was wealth and Antony wanted it along with Octavius. They had formed armies ready to fight Cassius and Brutus and Brutus had decided to take the fight to them.
With miscommunication Cassius, Titanius, and Brutus had all caused suicide even though they were winning the war. After all the events Brutus had been seen as a honorable man, even though his bad choices had caused most of the terrible events.