Although the Duke of Venice only appears in Act I, Scene 3, his position of authority gives him the power to significantly impact the trajectory of the play’s events. His first moments on stage show him devising a war strategy alongside his senators and other officers, a task which highlights his pragmatic and even-tempered nature. These qualities quickly establish him as a respectable leader who, in addition to being intelligent, is honest and just. He allows everyone in his counsel to share their knowledge and thoughts, and he makes judgements based on a genuine evaluation of what he hears. Given this measured approach, the Duke of Venice proves himself to be a very different kind of authority figure than Brabantio who, with his egotistical tendencies, often jumps to conclusions that inherently benefit his own worldview. Another way in which the Duke and Brabantio differ is in their opinion of Othello. While the latter becomes quite antagonistic toward the military general after learning of his marriage to Desdemona, the former values him for his excellence on the battlefield. The Duke treats Othello fairly and with the utmost respect, suggesting that he does not harbor the same kinds of racial biases as Brabantio. Between this accepting point of view and his calm demeanor, the Duke functions as an embodiment of stability and honor, qualities which quickly disappear once the play’s action moves to Cyprus. 

In terms of advancing the plot, the Duke makes two important decisions. He first chooses to mediate the dispute that emerges between Brabantio and Othello as a result of Desdemona’s elopement. After listening to both sides of the argument, he exonerates Othello, even going so far as to suggest that his own daughter would fall in love with him. This judgement is significant as it reinforces Othello’s reputation as an upstanding, heroic man. Knowing of his military successes, the Duke then elects to send Othello to Cyprus in order to fend off the Turks, and he gives Desdemona permission to accompany him. Sending Othello and the rest of the play’s primary characters into a foreign land invites chaos and uncertainty to fall upon them. While the Duke certainly does not intend for Othello to suffer, this new backdrop sets the stage for the tragedy that will ultimately befall him.