Castro was the principal asset which Drury Lane had to set that season
against Congreve's splendid adventure with Love for Love.

Agnes de Castro is an immature production, and shows a juvenile
insensibility to plagiarism, since the subject and treatment are
borrowed implicitly from a French novel by Mlle. de Brillac, published
in Paris and London a few years before.[2] The conception of court life
at Coimbra in the fourteenth century is that of this French lady, and is
innocent of Portuguese local colour. But, as the dramatic work of a girl
of sixteen, the play is rather extraordinary for nimble movement and
adroit theatrical arrangements. It is evident that Catharine Trotter was
well versed in the stage traditions of her own day, and we may wonder
how a highly respectable girl of sixteen found her opportunity. The
English playhouse under William III. was no place for a very young lady,
even if she wore a mask. There is a good deal of meritorious
character-drawing in Agnes de Castro. The conception of a benevolent and
tenderly forgiving Princess is well contrasted with the fierce purity of
Agnes and the infatuation of the Prince. Towards the close of the first
act there is a capital scene of exquisite confusion between this
generous and distracted trio. The opening of the third act, between
Elvira and her brother Alvaro, is not at all young-ladyish, and has some
strong turns of feeling. The end of the play, with the stabbing of the
Princess and the accusation of Agnes by Elvira, is puerile, but was
doubtless welcome to a sentimental audience. It is a bad play, but not
at all an unpromising one.

Early in 1696 _Agnes de Castro_, still anonymous, was published as a
book, and for the next five or six years we find Catharine Trotter
habitually occupied in writing for the stage. Without question she did
so professionally, though in what way dramatists at the close of the