The Original Story
Shakespeare used existing stories as the basis for many of the plots of his plays. He took some from history (Macbeth, for example is based on Holinshed's Chronicles) and some from stories that were circulating in books at the time. Shakespeare's tragedy Othello, written and performed in 1604 and first printed in 1622, is based on a tale in Cinthio's Hecatommithi (1565), "Un Capitano Moro." What's interesting to modern readers is how Shakespeare adapted these stories, turning bare narratives into gripping drama.
The original tale, "Un Capitano Moro," concerns an unnamed Moor who marries a beautiful lady, Desdemona, despite her parents' opposition. The Moor and Desdemona live happily in Venice, and the Moor is appointed commander of troops sent to the garrison at Cyprus. He takes his wife with him.
The Moor's wicked ensign falls in love with his commander's wife, Desdemona. The ensign is afraid he will be killed if the Moor discovers his secret, and all his efforts to impress Desdemona go unnoticed because she only thinks of her husband. The ensign imagines that she loves someone else, a handsome young captain who is also in Venice, and his love turns to bitter hatred. He plots to kill the captain and revenge himself on Desdemona.
The ensign bides his time. He sees his opportunity when the Moor degrades the captain for wounding a soldier and Desdemona tries to make peace between her husband and the captain. The ensign hints that Desdemona has her own reason to want the captain reinstated. When his wife claims that the demotion was an overreaction, the Moor becomes very angry and suspects that his ensign had spoken truthfully. When the ensign tells the Moor that the captain told him of the affair, the Moor demands to see proof of it.
The ensign and his wife have a daughter aged about three, and one day when Desdemona visits their house, he puts the child on her lap. As Desdemona and the child play, the ensign steals one of her handkerchiefs. The ensign then leaves the handkerchief on the bed of the young captain, who recognizes it and goes to return it to Desdemona. When the Moor answers his knock at the door, the captain runs away, but not before the Moor recognizes him.
Later, the ensign laughs and jokes with the captain where the Moor can see them; he then tells the Moor him that he and the captain were talking about the captain's love affair with Desdemona and a handkerchief that she had given him. The Moor, believing that the handkerchief constitutes proof of his wife's infidelity, demands it of his wife, who, of course, cannot produce it. The Moor decides that he must kill his wife and plots with the ensign to kill both his wife and the captain.
The ensign, after a large payment, waylays the captain, attacks him with his sword, and manages to wound him on the leg. Desdemona is tearful to see the captain in pain, and the Moor and the ensign beat her to death with a sand filled stocking. Then they pulled down the rotten timber ceiling on her, making it appear that the falling roof had killed her. The Moor, distracted with grief for his dead wife, turns against the ensign and cashiers him.
The ensign now plots to ruin the Moor. He goes back to Venice with the captain, now one-legged, and they accuse the Moor of injuring him and murdering Desdemona. The Moor is arrested, refuses to speak under torture, and is banished and later killed by Desdemona's family. The ensign pursues his career of villainy with other victims, but in the end is arrested and dies under torture.
For a complete retelling of this story, see The Arden Shakespeare: Othello, edited by M. R. Ridley. London: Methuen, 1965.
In creating his tragedy Othello, Shakespeare tightened and dramatized the original story in several ways. The plot is concentrated in time and space, other characters are introduced to give, in several places, a double motive for an action. Iago now plots to destroy Othello, for a variety of motives, rather than Desdemona. Roderigo provides Iago with a useful dupe; his existence allows Iago to outline his wicked plans in conversation rather than soliloquy and to demonstrate his capacity for ruthless manipulation. Emilia provides a running commentary on Iago and his character, which she ascribes to all men. She innocently picks up the handkerchief, allowing the elimination of the daughter from the plot, and is a quick source of the information that finally condemns Iago.
Shakespeare also significantly altered the story's ending, concentrating revenge, love, and despair in the final dramatic scene of the play: murder in the marriage bed, followed immediately by revelation and grief. Shakespeare's Othello murders his wife alone, face to face, by strangulation, struggling with his love for her to the end.
By concentrating the action and developing the characters into fully realized human beings, with their own names, personalities, and ways of looking at the world, Shakespeare created a tragedy whose beauty and pathos is universal.