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 Jews from the Kingdoms of Castile and Aragon (but not from the Kingdom of Navarre) and its territories and possessions by 31 July of that year.
That date in 1492 was the anniversary of the destruction of Temple in Jerusalem and was just three days before Columbus, with a crew of forcibly converted Jews and Muslims, set sail to bring Christianity to the new world.