This verse drama is Byron’s retelling of the Genesis story but with Cain as its hero, both in the sense of the play’s main character, and also as a version of what Byron himself admired and indeed constructed — “the Byronic hero”, which here reaches the final stage of its development. Like his other plays, Cain was a closet drama not intended for the stage, a type of romantic poem-drama like Goethe’s Faust or, later, Ibsen’s Peer Gynt. In fact it has since been performed, for example, by the Royal Shakespeare Company at the Barbican Pit in 1995, in a successful production directed by John Barton.
The play is subtitled A Mystery, by which Byron signals not a whodunit but a type of …
Forsyth, Neil. "Cain". The Literary Encyclopedia. First published 02 September 2016
[http://www.litencyc.com/php/sworks.php?rec=true&UID=6202, accessed 29 July 2017.]