William Shakespeare's The Merchant of Venice expertly blends tragedy, romance and comedy, the latter two categories closely connected. The main plot in Shakespeare's play involves the titular figure, Antonio, a businessman who borrows money from the Jewish moneylender Shylock in order to help his friend Bassanio court the beautiful and wealthy Portia. The tragedy lies in the nature of the agreement between merchant and moneylender. Shylock, bitter over the anti-Semitic treatment he has habitually received at the hands of Antonio, will only lend Antonio money if the latter agrees to forfeit a pound of his own flesh if unable to repay the loan. The relationship between the two, as well as the climactic courtroom confrontation in which Shylock makes his heartfelt plea for humanity ("Hath not a Jew eyes? hath not a Jew hands, organs, dimensions, senses, affections, passions?") provides the tragedy that infuses Shakespeare's play.
If The Merchant of Venice is a tragedy, it is also a comedy. Portia wants Bassanio as much as Bassanio wants her. That constitutes romance, but it is in the details of Portia's manipulation of the process her father set in motion to ensure she wed the proper gentleman that one finds the comedy. That process requires the successful suitor of Portia's hand to select the correct casket among several arranged in a room. Portia's efforts at helping Bassanio to choose correctly whilst discouraging other male visitors seeking to marry her provides the play's comedy.
Romance in The Merchant of Venice occurs along two parallel tracks. The first involves Bassanio and Portia, as discussed above. The second involves Shylock's daughter, Jessica, and Lorenzo, a friend of both Antonio and Bassanio. The latter relationship qualifies as romantic, but it also crosses over into tragedy. The defection of his daughter to Lorenzo and, by extension, to Antonio, Portia and Bassanio, is tragic to the defeated Shylock. Having already seen his arrangement with Antonio nullified in a trumped-up legal process, he must now endure his daughter's elopement with Lorenzo.