King Lear is a tragedy written by William Shakespeare. It is based on the mythological Leir of Britain. King Lear relinquishes his power and land to two of his daughters. He becomes destitute and insane and a proscribed crux of political machinations. The first known performance of any version of Shakespeare's play was on St. Stephen's Day in 1606. The three extant publications from which modern editors derive their texts are the 1608 quarto (Q1) and the 1619 quarto (Q2, unofficial and based on Q1) and the 1623 First Folio. The quarto versions differ significantly from the folio version. The play was often revised after the English Restoration for audiences who disliked its dark and depressing tone, but since the 19th century Shakespeare's original play has been regarded as one of his supreme achievements.