King Lear: The Use of Letters William Shakespeare used letters as a dramatic device to reveal the characters' loyalty and betrayal in his play King Lear. The purpose of the letter is to develop the plot and reveal the characters' attributes. Three letters help to develop the plot and reveal the characters of Edmund, Gloucester, Goneril and Albany. The first letter that appeared on the stage is Edmund's false letter. The letter talked about Edgar's plan to kill to his father, Gloucester. Edmund made up this letter to plan against his brother Edgar. Edmund lied to Gloucester about the letter. This letter developed the subplot in King Lear an