Measure for Measure is known to have been performed by Shakespeare's company at the Court of James I on December 26, 1604. It is generally presumed to have been written in the same year. The earliest printed text appeared in the First Folio, published in 1623. Confusions and imperfections in that text suggest that errors may have been made in transcription, and further, that the play may have undergone revision at some time prior to its first printing.
The basic plot which Shakespeare employed in Measure for Measure was not new to that play. Its ultimate source was a historical incident supposed to have occurred near Milan in 1547. A young wife prostituted herself to save her condemned husband. The magistrate who had forced the woman to yield to him proceeded to execute her husband. He was eventually made to marry the widow and was then put to death himself for his crime against her.
This incident was probably the basis of a story by Giraldi Cinthio, published in 1565 as the eighty-fifth novel in his Hecatommithi. The same plot was also put to use in Cinthio's Epitia, a dramatic version which appeared in 1583, some ten years after the death of its author. In 1578, after Cinthio's death, but before the publication of his dramatic version, George Whetstone, an English dramatist, wrote his Promos and Cassandra, using Cinthio as his source. The play was never performed, but a story based on it was included in 1582, as a tale in Whetstone's Heptameron of Civill Discourses.
Shakespeare probably was aware of all four of Cinthio's and Whetstone's versions of the basic plot. He may also have known of the original true incident and of other similar, supposed historic situations on record. However, Shakespeare departed from his sources in several areas. In considering Measure for Measure, it is important to be aware of the source versions and the changes Shakespeare made in adapting the plot for his own purposes.
In Cinthio's first version, Epitia is the sister of a young man condemned to death for the crime of rape. Juriste promises to pardon him if she will submit her body to him. She does, but Juriste has her brother executed anyway and cruelly sends her the body. She appeals to the emperor, who forces Juriste to marry her and then condemns him to death. Epitia begs for his life, and he is pardoned.
In Cinthio's later drama, a surprise ending is added. The Captain of Justice comes forward in the last act to inform Epitia that he spared her brother's life, sending her a substitute body. Having formerly refused to plead for her husband, she now begs for and is granted his pardon.
In Whetstone's version, the heroine is Cassandra, whose brother Andrugio is condemned to death for seduction rather than rape. She sacrifices her virginity to the demands of Promos, who breaks his promise of pardon for Andrugio, sending her his head. Cassandra takes her case to the king, who forces Promos to marry her and then condemns him to death. It is now learned that the jailer has spared Andrugio, substituting the head of another. When her brother is restored to her, Cassandra pleads for Promos's life, which the king spares.
In Shakespeare's Measure for Measure, Isabella's brother Claudio is condemned for getting his beloved with child. Isabella begs Angelo for his life, and he promises to spare her brother if she will yield to his desires. She refuses, but through the machinations of the disguised duke, Mariana takes her place in Angelo's bed. Convinced that he has lain with Isabella, he nevertheless orders the execution of her brother and asks that the head be sent to him as evidence. The duke persuades the Provost to save Claudio, substituting the head of another. In the final scene, Angelo is made to marry Mariana and is condemned to death. Isabella begs for his life and her prayer is granted by the duke. She then learns that her brother still lives.
The Shakespearean version of the story is different from the sources in several significant ways. It is a milder handling. For example, Angelo views the supposed head of Claudio himself, while his counterparts in Cinthio and Whetstone send the evidence of execution to the sister. Isabella pleads for Angelo before she learns her brother has been saved, while in Whetstone and in Cinthio's second version, the heroine only begs mercy for the magistrate upon learning of her brother's safety. Escalus is invented by Shakespeare to offer a dramatic contrast to Angelo. The humorous minor characters and the secondary action of which they are a part are Shakespeare's own.
But there are three major ways in which Shakespeare's version is at variance with the sources. First, the duke plays a major role in Measure for Measure, while his counterparts in the sources are merely introduced at the last minute to provide a solution to the conflict at hand. The duke's disguise, his manipulations of the other characters, and his proposed marriage to Isabella are all new in the Shakespearean version. Second, Isabella refuses to sacrifice her virginity to Angelo. She places her virtue above her brother's life. Her action presents a marked contrast to the background of moral corruption against which it occurs. As a result, the whole business of the substitute bed partner and the character of Mariana are introduced. And third, Shakespeare's heroine does not marry her tormentor. Isabella's virtue is paired in the final scene with the duke's goodness rather than with Angelo's vice.