The play opens with the Earl of Kent and Earl of Gloucester talking about King Lear's plans for 'the division of the kingdom'. Kent meets Gloucester's illegitimate son Edmund and learns he is a year younger than Edgar, Gloucester's 'son by order of law'. The King and all his court arrive and King Lear announces his plan to 'shake all cares and business from our state, / Conferring them on younger years' and calls on his three daughters to express their love for him before he rewards them with a share of his kingdom. His two older daughters, Goneril and Regan, offer poetic speeches but his youngest and favourite daughter Cordelia refuses, declaring 'I love your majesty / According to my bond, no more nor less'. Lear is angry and disowns Cordelia, giving her share of the kingdom to her sisters' husbands to divide between them. Kent, out of loyalty to both Lear and Cordelia, speaks up to tell Lear he is wrong, but Lear does not listen and banishes Kent from the kingdom.
The King of France and the Duke of Burgundy, rivals to marry Cordelia, are brought in and Lear tells them that she is 'new adopted to our hate / covered with our curse and strangered with our oath'. Hearing what has happened, Burgundy is no longer interested in marrying her but France declares 'Thy dowerless daughter, King, thrown to my chance, / Is queen of us, of ours, and our fair France.' After Lear and his court have left, Cordelia says goodbye to her sisters and leaves for France. Left alone, Goneril and Regan discuss their father's 'poor judgement' and 'unconstant starts'.