Ambition is a significant similarity between Creon in Sophocles's play Antigone and the title character Macbeth in Shakespeare's play Macbeth. More specifically, their similarity is the ambition to rule.
In Sophocles' Antigone, a primary reason Creon decreed the law denying Polynices's burial was to re-establish law and order in Thebes, especially to establish himself as the new King of Thebes. The city of Thebes has just undergone a great deal of political turmoil, and Creon is actually the fourth king crowned to rule over Thebes in a very small number of years. Prior to Creon, Oedipus was exiled, leaving his twin sons, Polynices and Eteocles, to rule jointly. The two brothers agreed to alternate possession of the throne each year; however, after only the first year, Eteocles, the younger brother, refused to step down and drove his brother into exile in Argos, where Polynices married the daughter of King Adrastus, Argeia. King Adrastus sent his army into Thebes to defend Polynices, but both brothers died killing each other in battle (Hellenica World Encyclopaedia, "Polynices"; Encyclopaedia Britannica, "Seven Against Thebes: Greek Mythology"). Hence, in Creon's mind, since Polynices attacked Thebes, Polynices is a traitor to the state and does not deserve burial, whereas, since Eteocles was defending Thebes, Eteocles is a hero of Thebes and does deserve a heroes burial regardless of the fact that, as the younger brother, he was keeping his older brother from his natural birthright. Therefore, in Creon's mind, in establishing the law denying Polynices' burial, Creon is trying to re-establish law and order in a devastated Thebes and to position himself as the new and trustworthy king, since he is next of kin of the deceased, as we see when he declares in his first speech in the play, "With laws like these I will make our city grow" (192-93).
Similarly, Macbeth also wants to establish himself as king, but his reasons are far less noble than Creon's. Creon is the rightful heir to the throne; Macbeth, on the other hand, must undertake a series of murders to try and secure the position of king. First, he kills the present King Duncan and the witnessing servants; then, he kills Banquo, who is expressing suspicion, and tries to kill Banquo's son Fleance, who may inherit Duncan's throne.