A few weeks ago, tens of thousands of people gathered in the streets of Manhattan, as they do each year, to celebrate the legacy of Christopher Columbus, discoverer of the New World. With pomp and ceremony, marchers crowded Fifth Avenue, filling it with an array of vivid costumes, colorful floats and lively music as part of the Columbus Day parade that has been held in New York since 1929.

Politicians and local dignitaries took part, as well as people from across the metropolitan area, in what has become a popular salute to the country's Italian-American heritage.

Now, however, there is compelling new evidence to indicate that they have been celebrating the wrong thing all along. Columbus, it seems, was neither Italian nor Spanish nor Portuguese. He was - believe it or not - a Jew.

That, at least, is the conclusion reached by Estelle Irizarry, a professor at Washington's Georgetown University, who studied Columbus's grammar, language and syntax in more than 100 surviving letters, diaries and documents that he penned.

Inconsistencies in his spelling along with numerous grammatical errors led Irizarry to deduce that Catalan, not Spanish, was the native tongue of the Great Navigator and that he hailed from Aragon in northeastern Spain.

But she also found that his style and punctuation corresponded with that of Ladino, the Judeo-Spanish dialect spoken by Spain's Jews. That, along with other aspects of his writings, led her to resolve that he was a Jew or a Converso (a Jewish convert to Christianity) who sought to hide his identity.

If Irizarry is right, then it might be more correct to refer to the man dubbed the Admiral of the Ocean Sea as Chaim, rather than Christopher, Columbus.

BEFORE YOU laugh this off as just another example of wishful thinking, it is worth noting that the mystery behind Columbus's origins has long been the subject of debate, and historians continue to disagree regarding the most basic facts of his life.

Columbus himself was famously vague about his heritage, telling those who asked, "Vine de nada" - "I came from nothing." As a result, researchers have variously suggested that he was the son of a Genoese wool-weaver, the illegitimate offspring of a Portuguese duke or even a member of a noble Greek family.

But a number of Spanish scholars, such as Jose Erugo, C. Garcia de la Riega, Otero Sanchez and Nicholas Dias Perez, all posited that Columbus was a Marrano, the derogatory term for Jews forcibly converted to Catholicism.

Additional proponents of this theory included the late Nazi-hunter Simon Weisenthal, whose 1973 book Sails of Hope argued that Columbus's 1492 voyage was motivated by a desire to find a new homeland for the Jews in light of their expulsion from Spain.

Say what you will, but the evidence is intriguing. Columbus adopted the Spanish last name Colon, which was common among Jews at the time. Upon his death, he reportedly left a part of his bequest to a converted Jew in Lisbon, and his son Ferdinand asserted in a biography of his father that his forefathers "were of the royal blood of Jerusalem."

Columbus's departure on his voyage to America coincided with the ultimatum given to Spain's Jews to leave the kingdom forever, and Jews and Conversos figured prominently among his financial supporters as well as his crew. As historian Cecil Roth noted in his book The Jewish Contribution to Civilization, "it is incontestable that the great explorer had a penchant for Jewish society and that Jews were intimately associated with his enterprise from the beginning."

These included Luis de Santangel, a descendant of converted Jews who provided the bulk of the funds to back the journey, as well as Don Isaac Abrabanel, the famed rabbi and royal financier.

Interestingly, Roth further notes that when Columbus reached the Americas, "land was first sighted by the Marrano sailor, Rodrigo de Triana; and Luis de Torres, the interpreter, who had been baptized only a few days before the expedition sailed, was the first European to set foot in the New World."

NOW, YOU might be wondering: does any of this matter? Should anyone really care if Columbus was a secret Jew? I think the answer is a definite yes. This is more than just a matter of historical curiosity. It is a point of pride, and yet another compelling example of how Jews throughout history have helped to make the world a better place.

Though Columbus never discovered the passage to Asia that he was seeking, he uncovered a new world and expanded the boundaries of mankind's thinking in addition to its understanding of the globe. And the colonization that came in his wake ultimately paved the way for the birth of America, with all the good that has entailed.

Of course, we may never know for sure whether Columbus was in fact a secret Jew. But there are certainly enough bits of evidence to buttress such a theory, and to justify making the case that he was indeed one of "ours."

So instead of leaving it to the Spaniards, Italians and others to lay claim to this historical celebrity, I think it is time for Israel and world Jewry to do so as well. Tributes and museum exhibitions should be organized and an effort made to highlight Columbus's Jewish background.

For at a time when anti-Semitism in America is on the upswing, and Washington is pressing Israel to make dangerous concessions, it would be nice to remind them of the debt they owe to those they would defame.