Christopher Eisgruber was working on a school project with his son Danny, then a fourth grader, when he made a stunning discovery. Eisgruber, who on July 1 becomes president of Princeton University, was raised Catholic, though he has identified as a non-theist ‏(he prefers the term over atheist‏) since adolescence, and was married in the Episcopal church. His son’s teacher asked students to look for relatives who came through Ellis Island, so on a March day in 2008 Eisgruber began searching its archives. On a ship’s manifest listing his mother and her parents, he found an unexpected notation: “Hebrew.”

After further scouring Ellis Island’s records, Yad Vashem’s database and, with a newfound cousin’s help, archives at the Center for Jewish History, Eisgruber, who is 52 and an expert in constitutional law, identified more relatives than he ever knew he had. He also learned that his Berlin-born mother, who arrived in New York as an 8-year-old refugee, and her parents were indeed Jews.

The discovery “was revelatory,” Eisgruber said in an interview with Haaretz. While it has not led to a wholesale embrace of religious identity, Eisgruber said that since then, he has participated in Passover seders, twice visited Israel and become involved with Israeli NGOs including the Peres Center for Peace. He will shortly publish a co-authored paper on models of equality and religious freedom in Israel. Today he describes himself as a non-theist Jew.

“Understanding myself as Jewish helps me understand who I am, what the experiences of my family are, and the set of cultural traditions from which I emerge,” he said. “For me it was a voyage of connection and discovery, and put me in touch with a wonderful set of people who have enriched my life tremendously.”

The discovery, reminiscent of that of former U.S. Secretary of State Madeleine Albright’s, was also unsettling. “I was disequilibrated. Bewildered at first. You think things are true about your childhood and suddenly you find things were very different. You think you knew your mother and grandmother,” he said. Eisgruber had been told that their mother, nee Eva Kalisch, was raised Protestant and converted to Catholicism before meeting their father. Her family had to leave Germany “for political reasons, because her father said things that offended the Nazis,” Eisgruber said. She also told her children that their father was an anti-Semite who had been in Hitler Youth. When they married, she instructed relatives she wanted no further contact, Eisgruber said, and “they had felt bound by these promises not to contact us.”

His mother, an only child, died five years before Eisgruber’s discovery. His maternal grandparents had also passed away. “I am certain my mother swore her mother [who lived near his childhood home] to secrecy − she would have cut her off from her grandchildren if she had spilled the beans,” Eisgruber said. As a child, he said, “I did occasionally ask our mother questions about her past and she had ways of deflecting. One of my sisters remembers asking her what our grandfather said that lead to their rapid departure and mother got very upset. So as a child you learn not to ask,” Eisgruber recalled. “I had asked my grandmother and she said ‘it was a very hard time for us, please don’t ask us about it.’ It never occurred to me that the family was Jewish.”

Sisters remain non-Jewish

His three sisters responded to the uncovering of their family history with varying levels of interest, he said. He is the only one who identifies as Jewish.

In 2009 they were awarded 162,500 Swiss francs from the Swiss banks’ Holocaust Claims Resolution Tribunal. They filed the claim “in the hopes that we might obtain information about my great-grandfather.” But the tribunal didn’t have any. When Eisgruber later found descendants of his great-grandfather’s brothers, most in Israel, he and his sister gave them part of the Swiss bank recovery.

Eisgruber attended Princeton as an undergraduate, then went to law school, clerked for a U.S. Supreme Court justice and worked as a law professor before returning to his alma mater, where he has been its provost.

His wife, Lori Martin, is Episcopalian. Their son Danny is now 15. “It goes to the core of my convictions that Danny ought to be able to decide for himself and follow his own star. He decided earlier this year that he wanted to be baptized, and was baptized in a ceremony in which I participated. He could also have been bar mitzvahed had he wanted to be,” Eisgruber said.

Eisgruber has been reading up on Jewish intellectuals and Jewish history, the work of Jewish novelists and philosophers, he said. When he thinks of his mother’s decision to cut off her Jewish history − even naming her son after the Christian messiah − he feels mostly sympathy, Eisgruber said.

“Those of us who have been so lucky to live in this country at this time cannot imagine what it was like to be on a day-by-day basis a refugee the way my mother’s family was. To have to go through that at such a young age had to have been searing in ways I can’t imagine. To have had to make all these sacrifices is extraordinary,” Eisgruber said. Discovering that he is Jewish “has connected me with traditions and people who now matter a great deal in my life. There aren’t many times you have this opportunity to rethink perspectives.” In all, said Eisgruber, “It’s a heritage that now matters a great deal to me. It has been a fascinating journey.”