With the reconquest of the Iberian Peninsula by Christians, Jews began to fear for their luck. However, at least in Portugal until the middle of the 15th century, they enjoyed relative freedom, although they had to pay exorbitant taxes.

They achieved great prominence in Portuguese public life, as diplomats, royal advisers, administrators, doctors, mathematicians, astronomers, traders and bankers (although most of the Jewish population was composed of people with much more modest professions, namely, tailors , shoemakers, weavers, shepherds and small traders). This projection began to generate discontent among the people, who felt that "Christianity was subject to Jewish jurisdiction". (as a friar in a letter to Don Afonso V complained). Such a climate of dissatisfaction became widespread and the Jews began to be victims of persecution and violence by the popular.

The situation in Spain from the middle of the 14th century already foreshadowed the fate that awaited Portuguese Jews. In Toledo, in 1355, 12,000 Jews died as a result of religious persecution; the number reached 50,000 in Palma de Mallorca, in 1391. With the start of operations of the Inquisition, or “Holy Inquisition”, in 1478, the fear spread among the Jews of Spain. Fearing for their own luck, thousands converted to Catholicism, while another sought refuge in Portugal. The volume of refugees increased dramatically when in 1492 the expulsion of Jews from Spain was decreed.

Most of the fugitives crossed the border into Portugal in search of shelter, under the eight-month transit license granted by King D. João II.

This large contingent of thousands of Jews (93 thousand according to the accounts of the contemporary Andrés Bernaldez) fugitives without goods and money has stirred the spirits of the Portuguese.

In addition to popular anger, immigrants had to deal with the cleverness of Dom João II, who saw an opportunity to profit from the misfortune of others: the king instituted the collection of two shields for each immigrant, so that they could remain in Portugal for eight months.

As at the end of the stay the Jews were unable to leave Portugal (there were not enough ships to transport them - or so it was said), the king ordered them to be sold as slaves. Children between two and ten years old were taken from their parents, baptized and taken to colonize the islands of São Tomé and Príncipe, where the majority did not resist the weather conditions.

Despite this, they still live on those islands descended from these Jews, who, as proof of extreme cultural resistance, still retain some Jewish customs.

With the rise of Dom Manuel I to the Portuguese throne in 1495, the enslaved Castilians were freed. However, the king's announced wedding to Princess Isabel of Spain put the Jews back in a tension. This is because the marriage contract included a clause that required the expulsion of heretics (Moors and Jews) from Portuguese territory, just as the Spanish kings had done in 1492.

King Manuel I tried to make the princess reconsider (since he needed the capital and technical knowledge of the Jews for his Portuguese development project), but it was all in vain. On December 5, 1496, Dom Manuel signed the decree for the expulsion of heretics, granting them a deadline until October 31, 1497 for them to leave the country. To the Jews, the king allowed them to opt for conversion or banishment, thus hoping that many would be baptized, even if only proforma.

The Jews, however, were not convinced and the vast majority chose to leave the country. When the king saw his strategy fall to the ground, he closed all ports in Portugal - except the port of Lisbon - to prevent his escape.

Since the Jews constituted an important part of the country's economic, cultural and scientific elite, the king wanted to prevent his escape and concentrated around 20,000 Jews in the port of Lisbon, waiting for transport to leave Portuguese territory. < / p>

In April 1497 the king ordered the kidnapping of Jewish children under the age of 14, to be raised by Christian families, which was done with great violence. In October 1497, those who still resisted conversion were dragged to the baptismal font by the people incited by fanatical clerics and with the complacency of the forces of order.

It was from these mass and forcible baptisms that the Marranos, or crypto-Jews, emerged who practiced Judaism in secret, although they publicly professed the Catholic faith.

"New Christians" they were never really well accepted by the "old Christian" population, who distrusted the sincerity of the converts' faith. This distrust evolved into explicit violence in 1506, when the Lisbon Pogrom took place. The plague has spread to the city since January, causing dozens of victims a day. In April, once again inflated by fanatical clergy, who blamed "new Christians" due to the calamity, the populace attacked them, killing more than two thousand of them, including men, women and children.

For Portuguese Jews, the Pogrom of Lisbon was the final straw. A new Jewish diaspora was beginning, and some headed for northern Europe, where they founded communities in the Netherlands and Germany. Others went to the south of France, and even to England. Some Jews preferred to return to the Middle Orient, having been well received by the Ottoman Turks.

The Portuguese Jews also arrived with the Dutch in the Portuguese-Brazilian captaincy of Nova Lusitânia, Pernambuco and, consecutively to the entire northern region of Northeast Brazil between the years 1630 to 1654. In Recife, capital of New Holland, they founded the first synagogue of the Americas, the Kahal Zur Israel Synagogue, under the direction of the great chakra Isaac Aboab da Fonseca, author of the first literary and religious texts written in Hebrew in the Americas.

With the Portuguese reconquest of the Northeastern Northeast of Brazil, and the prohibition of practicing Judaism, the community dispersed, with some returning to Amsterdam, others migrating to other Dutch colonies in South, Central and North America, and a portion remained, taking refuge in the hinterlands, interior of northeastern Brazil where they became crypto-Jews.

In New York, which was a Dutch colony with the name of New Amsterdam, a group of 23 Jews arrived from Recife in September 1654, where they founded the first Jewish community in that city.

Although the Jewish presence in the American continent dates from a century and a half before the conquest of the Dutch Company of the West Indies to the Northeast of Brazil, the converted Jews (New Christians) were part of the Portuguese expedition which, under the command of Captain Cabral , "discovered" Brazil on April 22, 1500.

Even after the abolition of the Tribunal do Santo Ofício, in 1821, crypto-Judaism continued to be practiced in Portugal, especially in Beira Interior, Trás-os-Montes and Belmonte.