Dido and Aeneas is an opera by the English baroque composer Henry Purcell, it was composed in 1689 and hence is given catalogue number Z. 626. It comprises of 3 acts and lasts, on average, for an hour.
It is based a story extracted from Virgil's Aeneid, of the legendary Queen of Carthage Dido, and the sailor Aeneas. When Aeneas and his crew are shipwrecked in Carthage, he and the queen fall in love. However, as it is he who is destined to found Rome, he must soon leave. She cannot live without him and awaits death.
It is a monumental work in both art music and, specifically, baroque opera -- and is remembered as one of Purcell's, amd perhaps England's, foremost operatic works. The libretto was written by Nahum Tate, and may be considered Purcell's only true opera, as compared with his other musical dramatic works such as King Arthur.
Perhaps the most famous part of the work is Dido's aria When I am laid.