Byron’s poetic drama Cain, written in Ravenna in the summer of 1821, presents the critic with some difficult questions. Why did Byron choose to write in this peculiar style? Is there anything in the suspicion, sometimes expressed as a bold opinion, that it is (at times) incompetent writing? Does it really have the strident polemical voice implied by its subject matter, and if so which species of political, religious and philosophical thought are at stake? How do we relate the play to the very different Don Juan, a poem rarely placed under the banner of a single ideology, but nevertheless composed either side of Cain?