French tragedy _Inès de Castro_, a piece published forty years
before, but the English audience of 1763 saw in it a compliment to the
King of Portugal, whose cause against Spain Great Britain had espoused
towards the end of the Seven Years' War. The preliminaries of peace had
already been signed, but the spirit of belligerency had not subsided; so
that the making of the only odious person in the play (the Queen) a
Spaniard, and having it end with a declaration of war against Spain, could
not fail to please a patriotic audience. Since nobody reads _Elvira_
any more, I shall venture to give an expanded version of Genest's outline
of the plot, in order to make the comments in Critical Strictures more
intelligible:

Don Pedro [son of Alonzo IV, King of Portugal] and Elvira [maid of honour
to the Queen, who is the King's second wife, and is mother of the King of
Spain] are privately married--the King insists that his son should marry
Almeyda [the Queen's daughter, sister to the King of Spain]--he
acknowledges his love for Elvira--she is committed to the custody of the
Queen--Don Pedro takes up arms to rescue Elvira--he forces his way into
the palace--she blames him for his rashness--the King enters, and Don
Pedro throws away his sword--Don Pedro is first confined to his apartment,
and then condemned to death--Almeyda, who is in love with Don Pedro, does
her utmost to save him--she prevails on the King to give Elvira an
audience--Elvira avows her marriage, and produces her two children--the
King pardons his son--Elvira dies, having been poisoned by the Queen--Don
Pedro offers to kill himself, but is prevented by his father.[7]

The play had a respectable run, in spite of its colliding with the
Half-Price Riots, but contemporary accounts appear to indicate that it
was not highly thought of by the judicious. I extract the following terse
criticism from a letter in the _St. James's Chronicle_ for 20 January,