To understand Oedipus Rex by Sophocles, one needs to know why the play was written, what makes a tragedy, and what has happened in Oedipus’s life before this play should be established. This play was written by Sophocles, who is considered one of the most influential and important of minds during Greek city-states high. It was written for the Great Dionysia. This festival was about four days long and many plays were performed. Many plays, like this one, were written for this occasion. At this point in time, Greece was falling because of the Peloponnesian war, this could be the reason why Sophocles wrote this tragedy. Another important piece of information one needs to know to better understand Oedipus Rex is the definition of a tragedy.