The Alhambra Decree (also known as the Edict of Expulsion) was an edict issued on 31 March 1492, by the joint Catholic Monarchs of Spain (Isabella I of Castile and Ferdinand II of Aragon) ordering the expulsion of practicing Jews from the Kingdoms of Castile and Aragon and its territories and possessions by 31 July, of that year. The primary purpose was to eliminate their influence on Spain's large converso population and ensure they did not revert to Judaism. Over half of Spain's Jews had converted as a result of the religious persecution and pogroms which occurred in 1391, and as such were not subject to the Decree or to expulsion. A further number of those remaining chose to avoid expulsion as a result of the edict. As a result of the Alhambra decree and persecution in prior years, over 200,000 Jews converted to Catholicism, and between 40,000 and 100,000 were expelled, an indeterminate number returning to Spain in the years following the expulsion.