The Sephardim of England

There is no record of Jews in Britain in Roman times, as against countries such as Spain, France and Germany. The earliest Jews arrived after the Norman Conquest in 1066. William of Normandy invited Jewish financiers from Rouen to come to England.
They prospered in England, mainly as moneylenders, but ultimately came up against prejudice from some of the Nobles, indebted to Jewish moneylenders. It culminated in the expulsion of the Jews from England in 1290. In subsequent centuries, the only mention of Jews was in connection with Physicians at Court, or musicians from Italy.
After the expulsion of Jews from Spain in 1492, and Portugal in 1497, and the establishment of the Spanish Inquisition, a group of Portuguese merchants settled in Britain, ostensibly Catholic, but consisting of Marranos (Jewish converts), many of whom were ready to revert to Judaism.
In 1656, Rabbi Menasseh ben Israel, from Amsterdam, where a community of Marrano Jews had established itself, fleeing from the Inquisition., and reverted back to Judaism, paid a visit to England to try and persuade the English Government to allow the Jews to settle again in England. He met Oliver Cromwell, who was favourably disposed to the idea
The Portuguese merchants immediately started a Synagogue in a house, and openly reverted to Judaism. Rabbi Menasseh officiated on one occasion. The Jewish community was established by Sephardim in England, and over the years attracted many Marranos from Spain and Portugal, trying to flee the Inquisition.
Many of the Portuguese merchants were wealthy and many of them achieved prominent positions in British society. The Sephardic community thrived and built its first Synagogue at Bevis Marks in London in 1701.
http://www.sephardicstudies.org/uk.html