What is ironic about the timing of Caesar's murder, in relation to preceding events?
Arguably, there is situational irony in Caesar's murder at the Capitol.
With situational irony, the expected outcome of an event doesn't occur—instead, something happens that is the opposite of what we might have predicted. It would seem, therefore, that what happens later to Caesar "in relation to the preceding events" is ironic because when Julius Caesar returns to Rome after the death of Pompey on the feast of Lupercal in Act I, he is initially received with great adulation and enthusiasm, so his death would not be expected later on. In short, the parades in Caesar's honor are situationally ironic; the love of the people, which usually helps someone stay in power, here causes the conspirators to murder Caesar.
Cassius begs Caesar to restore Publius Cimber to citizenship, but Caesar refuses,
I could be well moved if I were as you.If I could pray to move, prayers would move me.But I am constant as the northern star.... (3.1.63-65)
In Act III, scene i, there are two aspects of Caesar's death that might seem ironic to the audience. First, this great and powerful man was warned on several occasions that he would be killed on March 15th. The soothsayer warns Caesar to "beware the ides of March." His wife, Calpurnia, has just spent the night having nightmares about her husband's murder.Yet the man who has defeated so many enemies and is known as a tactical genius, ignores these warnings and openly walks into a trap designed to kill him. The most ironic thing, however, may be the fact that, in the moments immediately preceding his assassination, according to plan, Metellus approaches Caesar, begging him to repeal the exile of his brother. Caesar then gives a speech about his own greatness and unwaivering character. It is in this moment of boasting that the conspirators choose to begin the attack.