Bennett Greenspan clearly loves his job, but most of all he loves when he can do good on this Earth and find a good story, too.

He is the CEO of Family Tree DNA, a company he founded in Houston 16 years ago to help people find the secrets hidden in their DNA: long-lost relatives, or maybe links to nearly forgotten times long past.

The company has recently studied the genetic material of a number of people from northern Mexico and, Greenspan said, found an unexpected kink in the double helix. Some have a genetic link to Sephardic Jews, who lived in the Iberian Peninsula in the late 15th century.

The question is: Why?

Greenspan went looking and found the answer — and the story that goes with it.

The Spanish monarchy ordered the removal of all Jews from Spain in 1492, and the Portuguese king did the same four years later. Jews who stayed had to convert to Christianity.

This is where a man named Luis de Carvajal y de la Cueva sails into the picture. He was a Portuguese-born Spanish naval officer born in 1537 into a family of Jews who had converted, or more likely "converted.".

After a successful first voyage to New Spain. Carvajal was commissioned to return with a group of settlers. In an unusual but not unique move, he was allowed to take settlers who could not prove their Christian lineage for three generations back. In other words, he took a lot of former Jews, some or many of whom were only nominally Christian.

His land, known as Nuevo Reino de Leon, comprised Tamaulipas, as well as the states of Nuevo Leon and Coahuila, and other chunks of territory as well, including part of what is now Texas.

(He is also said to be the first Spanish person to set foot on Texas soil.)

Some of that land was claimed by other Spaniards, and things got nasty. Lawsuits were bad enough, but the ugliness soon turned to Carvajal's heritage. He was accused of covering up his sister's and her children's Jewish practices. He died in jail in 1591.

The crypto-Jews' hope of finding peaceful practice in the New World was dashed. Some of Carvajal's relatives changed their name to Lumbruso. Two Lumbruso nephews returned to Europe and became rabbis.

Some Jews remained, as well as some Conversos, or Catholics who also kept some traditional Jewish practices, but others melted into the general populace, waiting for Bennett Greenspan and people like him, centuries later, to find their traces.

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