The Sephardim, that relatively small but very distinguished group of Orthodox Jews, achieved prosperity during the centuries Spain lay under Arab domination. More welcomed by the crescent than the cross, they served the conquerors as officials and administrators, stamping the country with their imprint. But when the Christians ousted the Moors in the 15th century, Jews were no longer welcome. Where could they go? Many opted for the New World, settling principally in New York. Industrious and intelligent, they entered business and the professions. They made money in trade and banking. And they closed ranks to form one of the least permeable and most durable aristocracies in our democratic country.