Othello Act 1 Scene 1

The play begins in Venice at night:

Iago was frustrated and irritated that Michael Cassio was made Lieutenant by Othello (the army general) whilst Iago was made ensign (third-in-command). Iago strongly believes that he has more practical experience in regards to the army as opposed to Cassio whose knowledge is derived from literature and books. 

Forsooth, a great arithmetician,/One Michael Cassio, a Florentine/(A fellow almost damned in a fair wife)/That never set a squadron in the field,/Nor the division of a battle knows/More than a spinster—unless the bookish theoric

Iago is bitter and holds Cassio in contempt for he feels like he has the greater right to be the ensign (also referred to as 'ancient'). Iago speaks of his woes to Roderigo, a man who feels cheated as Desdemona, a young Venetian aristocrat, has married Othello (the Moor). At this point, we learn that Iago has been taking money from Roderigo in exchange for promoting a marriage between Desdemona and Roderigo- he feels that his money has been wasted.

Iago reassures him by telling him that he hates Othello and wishes to extract revenge from him by angering Desdemona's father, Brabantio by telling him that his daughter has eloped with Othello.

Call up her father./Rouse him. Make after him, Poison his delight,/Proclaim him in the streets. Incense her kinsmen,/And, though he in a fertile climate dwell,/Plague him with flies. Though that his joy be joy/Yet throw such changes of vexation on’t,/As it may lose some color.

Iago openly declares his disloyalty to Othello.

Were I the Moor, I would not be Iago./In following him, I follow but myself./Heaven is my judge, not I for love and duty,/But seeming so, for my peculiar end.

We get the impression that Othello clearly trusts Iago for he made him the ensign. The ensign's role is to hold the flag of the army which holds his allegiance throughout the battle. The ensign must be both brave and loyal. However, we can also see that Iago's intentions are defiled by jealousy thus creating…