I grow, I prosper."(1.22.19-21).
He then decides to ruin Edgars reputation by lying to his father that Edgar is planning to kill him. He makes a fake letter which claims that Edgar is planning to kill Gloucester and shows it to Gloucester on purpose. He pretends to be faithful to his father Gloucester when he accuses his brother Edgar, and definitely, he gains Gloucester's trust. Edmunds action is driven by envy. He is jealous of Edgar not only because Edgar can inherit Gloucesters title, but also because Gloucester puts all his attention on his lawful son Edgar. His jealousness drives him to be a greedy person.
One of facts that determine a persons power is wealth. If a person has more money, then he or she can be more powerful. Edmund understands this fact and he is trying to gain more wealth in order to be powerful. First, he accuses his brother Edgar being unfaithful to his father Gloucester. His accusation is not only because of his jealousness towards Edgar, but also because of his greed. It is because if Edgars inheritance is abolished, Edmund can inherit his fathers possessions. In order to make Gloucester believes his lies, he makes a fake letter which imitates Edgar's hand-writings, he then asks Edgar fights with him in front of Gloucester and makes Gloucester believe that Edgar is harmful and evil.
Gloucester "You know the character to be your brother's?".
Edmund "If the matter were good, my lord, I durst swear it were his; but in respect of that, I would fain think it were not.
Gloucester "It is his.".
Edmund "It is his hand, my lord; but I hope his heart is not in the contents."(1.2.63-70).
Eventually, Gloucester believes in Edmund and Edgar is exiled. After kicking Edgar out of the picture, Edmund tries to gain more power by having affair Lear s evil daughters Coneril and Regan. He understands that lust can control a person completely. He also realizes that one of them will be the queen of England, if he gets married with the queen, he will become the king of England, who is the most powerful person in the country.