Why does Shakespeare move the setting of the play Othello to Cyprus?
The transition of setting from Venice to Cyprus puts Othello outside the immediate control of Venician authority and Desdemona beyond the disapprobation of prating Brabantio. It is the 'fleshing out' of sorts of their free will. An isolated military outpost symbolises both deliberate alienation from the norm and independance from control. Also, such liberty from primary influence serves as the vehicle for their respective natures to fully evolve and take hold.
But is such liberty too much? Here Othello's rashness and credulity- his double tragic flaw - is not held in check, for the 'veracity' of Iago and the sincerity of his friendship are never even put in question. As for Desdemona, her will melts before her idolation (and idealization) of her husband and she falls prey to Iago's perverse machination. She can no longer counter or even contest Othello's accusations once he is emported by rage. A subtle polarization of temperament has taken over. Whereas Desdemona weakens, Othello's hotheadedness now takes full rein and he loses control, he loses Desdemona, and he loses his life.
Shakespere change the setting of the play from Venice to Cyprus so that all the characters are removed from the burning effects of the civil society and are released from Venice's influence and authority over them. It gives them independence from the "controlled" world they had.
It gives them liberty and gives them a portal to express their freedom and let their nature matarialized and evolve and take control over themselves