Shakespeare’s Hamlet has some pretty disparate possible literary sources:
There’s an Scandinavian epic titled Saga of Hrolf Kraki, where the sons of a murdered king assume different identities in order to avenge their father.
There’s also the Roman legend of Brutus, not Julius Caesar’s Brutus, but as it happens (supposedly), one of his ancestors, who acted stupid (brutus being Latin for “dullard”) in order to escape detection when trying to overthrow his uncle.
There’s Amlodi, the Icelandic hero, who is an analog for the Scandinavian figure Amleth (Amleth… Hamlet). In this legend, retold by Saxo Grammaticus in the 13th century, Amleth was the son of Horvendill, the King of Denmark, who was killed by his brother Feng, who marries Horvendill’s wife, Amleth’s mother. Amleth pretends to be a fool to escape suspicion, but ends up killing an eavesdropper who hides in Amleth’s mother’s bedroom. Feng attempts to get rid of the prince by sending him to Britain with two men who were supposed to deliver the instructions of death from Feng. Amleth swaps the letter with one of his own, calling for the execution of the two fellow travelers, and the marriage of Amleth to the British king’s daughter. When Amleth returns to Denmark, he kills members of the court by trapping them in the palace and setting it ablaze, while he kills Feng with his sword. The adventure goes further to have him return to Britain and again to Scandinavia.
In 1570, Francois de Belleforest (yes, the same Belleforest who translated Matteo Bandello’s Nouvelle, which was a possible source for Twelfth Night), translated the Saxo work in Histoires Tragiques. Belleforest’s version is nearly twice as long as Saxo’s and spends more detail on Amleth’s personality, including his melancholy.
Then there was an earlier version of the play, now called by critics as Ur-Hamlet, which appears in theatrical accounts from before 1590. It could have been written by Thomas Kyd. Even if Kyd is not the author of the Ur-Hamlet, Shakespeare was influenced by his work, here in Hamlet as earlier in Titus Andronicus, since Kyd wrote the first famous English revenge tragedy, The Spanish Tragedy. In many of the revenge dramas, the play-within-a-play is often the conclusion of the play, during which the revenge and bloodletting takes place. Or Ur-Hamlet could have been written by Shakespeare. What it can not be is: “read today,” as no copy exists. But according to reports, it did include the Ghost of old Hamlet, something not in the earlier versions of the story, who urges his son on to revenge. Since it cannot be read, we’ll never know how much Shakespeare took from this earlier version (or if he wrote it), or from any of the other literary sources noted above.
[those who catch my repeated use of the term literary are to be applauded… and I’ll touch upon other possible sources later in our discussions…]