There are a number of articles and books that claim that Christopher Columbus has Jewish acenstry:
Christopher Columbus: Jewish Virtual Library
The mystery regarding Columbus' origins is largely the outcome of his own mendacity: and as a result it is equally impossible to exclude or to confirm the hypothesis that he was descended from a Jewish or ex-Jewish family.
Sails of Hope: The Secret Mission of Christopher Columbus, by Simon Wiesenthal.
According to Wikipedia:
Simon Wiesenthal postulates that Columbus was a Sephardi (Spanish Jew), careful to conceal his Judaism yet also eager to locate a place of refuge for his persecuted fellow countrymen. Wiesenthal argues that Columbus' concept of sailing west to reach the Indies was less the result of geographical theories than of his faith in certain Biblical texts—specifically the Book of Isaiah.
Christopher Columbus and the Participation of the Jews in the Spanish and Portuguese Discoveries, by Meyer Kayserling
Christopher Columbus's Jewish Roots by Jane Frances Amler.
Did Christopher Columbus have Jewish ancestry?