Final answer:
In Shakespeare's play 'Othello', Cassio is to replace Othello as the governor of Cyprus according to Lodovico's letter.
Step-by-step explanation:
According to Lodovico's letter in William Shakespeare's play Othello, Cassio is to replace Othello as the governor of Cyprus. This crucial piece of information is revealed towards the end of the play, marking a significant turn in the tragic downfall of Othello. It is one of the contributing factors to the series of events that lead to the climactic resolution of the plot.