Mainly because of persecution, Muslims and Jews in Spain at that time found it socially, politically, and economically expedient to convert to Catholicism (see "Converso", Morisco, and Marrano). The existence of superficial converts (i.e., Crypto-Jews) was perceived by the Spanish monarchs of that time (King Ferdinand and Queen Isabella) as a threat to the religious and social life of Spain. This led Torquemada, who himself had converso ancestors, to be one of the chief supporters of the Alhambra Decree that expelled the Jews from Spain in 1492.