Amadigi di Gaula (HWV 11) is a "magic" opera in three acts, with music by George Frideric Handel. It was the fifth Italian opera that Handel wrote for London and was composed during his stay at Burlington House in 1715. It is based on Amadis de Grèce, a French tragédie-lyrique by André Cardinal Destouches and Antoine Houdar de la Motte. Charles Burney maintained near the end of the eighteenth century, Amadigi contained "...more invention, variety and good composition, than in any one of the musical dramas of Handel which I have yet carefully and critically examined.”
The opera received its first performance in London at the King's Theatre in the Haymarket on 25 May 1715. Handel made prominent use of wind instruments, so the score is unusually colorful, and at points resembles the Water Music, which he composed only a few years later. An exceptional care was lavished to the production. Amadigi employs no voices lower than alto and it ends in a minor key. The opera was a success and received a known minimum of 17 further performances in London through 1717.
The identity of the librettist is not known for certain. Previous consensus had been that John Jacob Heidegger, who signed the dedication to Richard Boyle, 3rd Earl of Burlington was the author, but more recent research has indicated that the librettist was more likely to be Giacomo Rossi, with Nicola Francesco Haym as a more probable candidate. This libretto is an adaptation of a medieval Spanish knight-errantry epic Amadis de Gaula in which the King of Gaul educated in Scotland, falls in love with and eventually marries Oriana, daughter of the King of England.