In the beginning of King Lear, Edgar is established as a legitimate son and Edmund as a bastard son of Gloucester. This forms a conflict of power between the two brothers that ignites after Lear gives away his land and begins his slow demise. Edmund convinces Edgar that he has been banished by Lear, then accusing Edgar of a violent crime in order to receive inheritance.
Before this, Edgar had been trying to find purpose as a loved and wanted person as opposed to his brother according to societal standards, motivated by the promise of money. Because Edgar does not have any control over Edmund’s inheritance, Edmund sees no other alternative other than to kill his brother.
“Who gives anything to Poor Tom … that hath laid knives under his pillow and halters in his pew, set ratsbane by his porridge, made him proud of heart to ride on a bay trotting horse over four-inched bridges to course his own shadow for a traitor?”III.IV.58-61
Then, disguised as Poor Tom to avoid being killed, Edgar clearly sees the shadow of power his brother has lived in and how he has been taken advantage of by Edmund. As someone born into wealth, he would be deemed a traitor and judged. However, disguised as a beggar, he is pitied and free from judgement or societal expectations.
While Edgar is in disguise, he plays the role of a peacekeeper amidst the conflict started by Lear. He helps his father, Gloucester, who was condemned as a traitor and had his eyes plucked out for his compassion towards Lear, die at peace.
By the end of King Lear, Edgar is able to take revenge for the suffering Edmund has caused him. He escapes the shackles of societal expectations and is able to save himself while other characters perish. This gives him the opportunity to get a second chance at approaching life with a fresh perspective on the impact of power and social constructs such as class.