The Dominicans on their side can scarcely be credited with a pure zeal for the faith.

They had personal interests to serve by spiritual aggrandizement, by the elevation of their order, and by the exercise of an illimitable domination.
It was a Sicilian Inquisitor, Philip Barberis, who suggested to Ferdinand the Catholic the advantage he might secure by extending the Holy Office to Castile.

Ferdinand avowed his willingness; and Sixtus IV.
gave the project his approval in 1478.

But it met with opposition from the gentler-natured Isabella.

She refused at first to sanction the introduction of so sinister an engine into her hereditary dominions.