It is a somewhat extraordinary circumstance, that the Spanish and Portuguese Israelites consider their German and Dutch brethren as vile remains of the tribe of Benjamin. With regard to themselves, they affirm that they are descended from the tribes which Nebuchadnezzar had transplanted to the banks of the Euphrates. The Arabian Caliphs, becoming masters of Asia, extended their conquest, by degrees, to Spain, where several Jewish families came to establish houses of commerce; and where they multiplied to such a degree, that, if we may believe them, all the families, both in Spain and Portugal, most distinguished for noble birth or opulence, are of Jewish extraction. The Spanish and Portuguese Christians warmly defend themselves from this imputation. They prefer, contrary to all probability, representing themselves as descended from Visigoth or Arian soldiers. Strange enough, for the Jewish race, being the most ancient, is consequently the noblest, in the world.
These Jewish families, after the establishment of the Inquisition, found means to compromise matters with that body. For money, and external conformity to the Christian religion, the inquisitors winked at them: they gave vent to their rage only against such fanatics as were obstinately determined to get themselves burnt. Tired of such a state of constraint, disgusted with the contempt which accompanied it, and allured by the tolerating spirit of the English, the Spanish and Portuguese Jews crossed the seas in great numbers, with immense wealth. From 1720 to 1740, the number exceeded twenty thousand.
Honoré-Gabriel de Riquetti Mirabeau. Mirabeau's letters during his residence in England: with anecdotes ..., Volume 2. 1832