Court case(1852) 1 De G M & G 604

Johanna Wagner, a celebrated opera singer, agreed with Benjamin Lumley to sing at Her Majesty's Theatre, London, for three months, and expressly undertook not to use her talents at any other theatre during that period without his written permission. Frederick Gye of the Covent Garden theatre persuaded her, for a larger fee, to abandon Lumley and sing for him. Lumley sought an injunction.

Lord St Leonards LC granted the injunction. The court could not and would not compel Wagner to sing at Lumley's theatre, but it could restrain her from breaking her express negative promise not to sing elsewhere. Enforcing the negative part might in practice persuade her to perform the positive part, but that was no objection: the court was simply holding her to a promise she had freely made, and the injunction did no more than prevent the wrong.