The King of Britain, in an attempt to avoid future strife, divides his kingdom between his three daughters.
His eldest two, Regan (wife of Cornwall) and Gonerill (wife of Albany), respond to his request for a show of love, but Cordelia is unable to, not wanting to be hypocritical. In a fit of rage, Lear banishes her, and she leaves to marry the King of France. When his advisor Kent attempts to tell Lear he is doing wrong, he too is banished.
The Earl of Gloucester’s bastard son Edmund is planning to gain his brother Edgar’s lands by disinheriting him. He convinces Gloucester that Edgar is plotting against him, and then persuades his brother to flee from his father’s anger. To avoid arrest, Edgar disguises himself as a mad beggar, Poor Tom.
Lear begins a series of visits to Gonerill and Regan, followed by a disguised and loyal Kent. Kent insults Gonerill’s steward Oswald, and Lear takes him into his service. Gonerill then quarrels with Lear, who leaves her castle to go to Regan’s. Kent is sent ahead, but he quarrels again with Oswald, and is put in the stocks by Regan, who supports her sister’s attitude. The sisters meet together with Lear, and tell him to dismiss some and then all of his followers.
He leaves the castle in a rage, going out into a violent storm accompanied only by his Fool and Kent. Lear harangues the storm, then meets Poor Tom, whom he treats as a counsellor. Gloucester tells Edmund of his intention to help Lear, and advises Kent to take Lear to Dover, where Cordelia and a French army are to be found. But Edmund has informed on Gloucester to Cornwall, and when Gloucester returns to the castle he is accused of being a traitor, his eyes are put out, and he is thrown out into the wilderness. In the melee, Cornwall is killed by a servant.
Edgar encounters his blind father, and, as Poor Tom, journeys with him to Dover, where Gloucester finds Lear. There is growing animosity between Albany and Gonerill, who is showing increasing affection to Edmund, who also has a liaison with Regan. Oswald, taking a letter from Gonerill to Edmund, encounters Gloucester, but before he can harm him he is killed by Edgar. Lear is found by Cordelia’s army, and they are reconciled, but they are then taken prisoner by Edmund’s soldiers, and Edmund orders them both to be killed.
After the battle, Gonerill and Regan both encounter Edmund and display their feelings for him. Albany challenges Edmund, and a disguised Edgar appears to fight him. Regan dies, poisoned by Gonerill, and Gonerill takes her own life when her husband hears of her betrayal. Edmund is fatally wounded, and Edgar reveals himself.
An order is sent to cancel Lear and Cordelia’s execution, but it arrives too late to save Cordelia. Lear carries her in, and soon after dies of a broken heart. Albany abdicates, leaving Kent and Edgar to rule the realm; but Kent announces that he has a journey to go on like his master. Edgar reflects on the future.