There are many possible texts that Shakespeare could have used in constructing The Merchant of Venice, and while we can confirm that he relied upon two particular sources, the others sources I will mention were likely, though not definitely, influences on Shakespeare. His chief source was a tale in an Italian collection entitled Il Pecorone or The Simpleton, written in 1378 by Giovanni Fiorentino, and published in 1565. No known English translation existed for Shakespeare to use, but it is possible, although very unlikely, that someone Shakespeare knew had translated his own private copy and gave it to Shakespeare to read. It is more likely that Shakespeare was more learned than people like to assume, and that he read the text in its original Italian. The story in Il Pecorone tells of a wealthy woman at Belmont who marries an upstanding young gentleman. Her husband needs money and has friend, desperate to help, goes to a money-lender to borrow the required cash for his friend. The money-lender, who is also a Jew in Il Pecorone demands a pound of flesh as payment if the money is not paid back. When the money is not paid in time, the Jew goes to court to ensure he receives what he is owed. The friend’s life is saved when the wealthy wife speaks in court of true justice and convinces the judge to refuse the Jew his pound of flesh. Shakespeare adds the casket story line and the Shylock’s usury — in Il Pecorone the Jew lends the friend money without interest.
Portia’s suitors and the game of casket choosing they must play for her hand in marriage are from the Gesta Romanorum, a medieval collection of stories translated by Richard Robinson, and published in 1577. Here is the excerpt from Gesta Romanorum relevant to The Merchant of Venice, as reprinted in the edition of Shakespeare’s play edited by H. H. Furness:
Then was the emperour right glad of her safety and comming, and had great compassion on her, saying: Ah faire lady, for the love of my sonne thou hast suffered much woe, nevertheless if thou be worthie to be his wife, soone shall I prove. And when he had said thus, he commanded to bring forth three vessels, the first was made of pure gold, beset with precious stones without, and within full of dead mens bones, and thereupon was ingraven this posey: Whoso chooseth me shall finde that he deserveth. The second vessel was made of fine silver, filled with earth and wormes, and the superscription was thus: Whoso chooseth me shall finde what his nature desireth. The third vessel was mad of lead, full within of precious stones, and the superscription, Whoso chooseth me shall finde what God hath disposed to him.
In addition to the aforementioned sources, Shakespeare could have relied upon a play called The Jew. No copy of this play exists and the only acknowledgement of it ever existing comes from a book called Schoole of Abuse (1579), by Gosson. He mentions briefly that a play by that name was once performed at the Bull Inn, but no other details are known. He also could have used a novel called Zelauto, written by the English playwright Anthony Munday in 1580. Similarities exist between Jessica and one of the female characters in that text. Lastly, in approximately 1591, http://shakespeare-online.com/biography/shakespearecontemps.htmlChristopher Marlowe wrote The Jew of Malta. Marlowe, considered by most to be the greatest playwright other than Shakespeare in the English language, crafted his hero, Barabas, the wealthiest Jew in Malta, no doubt from the same sources as Shakespeare used. Barabas is cunning and extremely intelligent, but his intellect prompts his downfall, and he dies in the trap that he set for his enemy. Marlowe’s play was a wild success, and its popularity may have been the reason why Shakespeare decided to write his own version of the tale told in Il Pecorone.