King Arthur, or The British Worthy is a semi-opera by Henry Purcell and a libretto by John Dryden. It was first performed in June 1691.
The plot is based on the battles between King Arthur's Britons and the Saxons, rather than the standard legends of Camelot (although Merlin does make an appearance). It includes such supernatural characters as Cupid and Venus plus references to the Germanic gods of the Saxons. The tale centres on Arthur's endeavours to recover his fiancée, the blind Cornish Princess Emmeline, who has been abducted by his arch-enemy, the Saxon King Oswald of Kent.
In 1995 BBC Radio presented Fairest Isle, a dramatised story about the creation of this opera written by Steven Wyatt.