In William Shakespeare's Othello there is a wide array of themes. One of the themes, which is found true to nearly every character, is of the act of control throughout the play. Another theme portrayed through Iago, is the recurring use of words such as "monkey", "lion", etc. in "romantic" conversation.
In Othello, characters such as Roderigo, Brabantio, Desdemona, etc. at one point of the play believe that they have complete control over another character or situation only to find that the person or situation is uncontrollable. For instance, in the first scene of the play Roderigo is interested in courting Desdemona so he pays Iago to intercede with her on his behalf. Roderigo now believes that his money has bought him complete control over Iago, but when he finds out of Othello and Desdemona's marriage, he is angry at Iago and tells him,"I take it much unkindly that thou, Iago, who hast had my purse as if the strings were thine, shouldst know of this." However throughout the play Roderigo is still convinced that his money is helping to control Iago, and by the time he finds out that he has lost control, he has already been mortally wounded by Iago. Another example of this theme occurs between the main characters of the play Othello and Iago. Since Othello is a seasoned warrior and leader of the Venetian army, he believes that everyone underneath him will abide by his rulings and commands. And since Othello has had a long term relationship with Iago, he has even more trust and faith in him. But Iago sees this and decides to take advantage of Othello. This is first observed when Iago and Roderigo are speaking of their plan to get Othello against Cassio. After Roderigo exits, Iago lets the audience know of how he will be able to control and lead Othello around. Because of this Othello, who was the controller, has now become controlled by Iago. And the final example that the theme of control is present in the play Othello portrayed through Desdemona. This occurs at the point in the play after the fight between Cassio and Roderigo. Cassio is begging of Desdemona to help him get his job back as lieutenant of the Venetian Army. The newlywed Desdemona is so positive that she can convince Othello to reconcile with him, that she promises Cassio:
Do not doubt that: before Emilia here I give thee warrant of thy place.
Assure thee, If I do vow a friendship, I'll perform it to the last article.
My lord shall never rest...

This however is not what happens. When Desdemona brings this favor to Othello
he had just received a letter from Venice that ordered him back home. Othello misinterprets Desdemona's question and goes into a rage, striking here. This proves the theme of control because Desdemona believed that she had complete control over her husband Othello. But later on she finds out that he is beyond being controlled by her, in fact despite her pleadings at the end of the play, Othello is so out of control that he murders Desdemona.
Another recurring theme in William Shakespeare's Othello is shown through the character of Iago. Throughout the play Iago uses animals in descriptions and similes of passionate events or people. For instance in Act I, Iago and Roderigo have just found out about the marriage of Othello and Desdemona. Both of them rush over to Brabantio's house in the middle of the night, to tell him the news. While Iago is yelling up at his bedroom window he informs Brabantio:
...Your heart is burst, you have lost half your soul. Even now, now,
very now, an old black ram is tupping your white ewe. Arise, arise!
Awake the snorting citizens with the bell, Or else the devil will make
a grandshire of you.
The old black ram is obviously alluding to Othello and Desdemona is of course the white ewe. The "tupping" refers to Othello and Desdemona having sex with one another. A little later on in the play Iago is still talking with Brabantio about Othello and Desdemona. Iago keeps alluding to the marriage, but Brabantio is not quite sure what Iago is trying to say. So Iago makes the advice a little more obvious by telling him that the Moor (Othello) and his daughter are making a beast with