The first performance was at the Teatro Colón, Buenos Aires, Argentina on 24 July 1964 with Carlo Cossutta in the title role.

In November 1967 the production was also given, still with Plácido Domingo, on tour at the Dorothy Chandler Pavilion in Los Angeles.

Ginastera prepared from the opera a concert work for soprano and orchestra, which received its own first performance in October 1964.

Malena Kuss has published a detailed study of Ginastera's use of motives and of Argentine musical idioms in the opera.

Historically, a chest in the Vault of Hercules has contained a locked mystery, which every King of Spain has respected since ancient times.

However, Rodrigo opens the locked chest, where he sees the secret in the form of an Arab flag and a curse.