In 1492, King Ferdinand II of Aragon and Queen Isabella I of Castille issue the Alhambra Decree, mandating that all Jews be expelled from the country. This comes not long after they had conquered the Nasrid Kingdom of Granada, finally freeing Spain from Muslim rule after nearly 800 years.

In 1478, Ferdinand and Isabella, whose marriage and conquests cemented Spain as a unified kingdom, had instituted the Inquisition, an effort by Spanish clergy to rid the country of heretics. Pogroms, individual acts of violence against Jews and anti-Semitic laws had been features of Catholic Spain for over a century before the Alhambra Order, causing deaths and conversions that greatly reduced Spain’s Jewish population. Having already forced much of Spain’s Jewish population to convert, the Church now set about rooting out those who suspected of practicing Judaism in secret, oftentimes by extremely violent methods. Tomas de Torquemada, the Grand Inquisitor, is said to have petitioned the monarchs to expel all Jews for years before they finally issued the order on March 31, 1492.

The results were catastrophic. Jews were given until the end of July to leave the country, resulting in the hasty selling of much of their land and possessions to Catholics at artificially low prices. Many converted in order to remain in Spain, with some continuing to practice their religion in secret and others assimilating into Catholicism. Estimation is difficult, but modern historians now believe around 40,000 Jews emigrated, with older estimates putting the number at several hundred thousand. Many died trying to reach safety, and in some cases it is believed that refugees paid for passage to other countries only to be thrown overboard by Spanish captains. While the Ottoman Empire welcomed the influx of Spanish Jews, many other nations in Europe treated them as cruelly as the Spaniards—though Portugal was a popular destination, its rulers issued a similar decree five years later.

Communities established by Spanish Jews, known as Sephardim in Hebrew, formed the foundation of the Sephardic communities that now make up a significant percentage of the world’s Jewish population. The year of the Alhambra Decree was also the year that Christopher Columbus, sailing for Spain, “discovered” the Americas, and thus it marks the beginning of two centuries of Spanish efforts to force its Catholicism on its substantial colonial holdings. Spain has never had a significant Jewish population since; current estimates put the Jewish population of Spain at lower than .2 percent. Spain formally revoked the Alhambra decree in 1968, and in the early 2000s both Spain and Portugal granted Sephardic Jews the right to claim citizenship of the countries that expelled their ancestors 500 years before.