As a teenage partisan in the Ukrainian forests during World War II, Sonia Shainwald Orbuch knew she would someday write her memoirs. She vowed she’d even go so far as to tear bark off trees to use as paper.

But that promise was impossible to keep while fighting the Nazis, seeing beloved family members perish, then coping with post-Holocaust tragedy.

Sonia Shainwald Orbuch

At age 83, Orbuch finally felt the time was right.

The Corte Madera resident has published “Here, There Are No Sarahs,” which she co-wrote with historian Fred Rosen-baum. The book chronicles Orbuch’s idyllic childhood, the nightmare of the German invasion, her service with anti-fascist partisans and her postwar life in the United States.

She and Rosenbaum will speak Wednesday, May 20 at the Osher Marin Jewish Community Center.

“This has been weighing on me for all these years,” Orbuch says. “I promised myself when I had the opportunity, I would write. Then I got married and had a family. But I never forgot the promise to myself.”

It’s easy to see why. Orbuch’s story doesn’t fit neatly into preconceived notions of Holocaust survivors. Orbuch fought back.

Born Sarah Shainwald in the Polish shtetl of Luboml (now in Ukraine), she grew up with doting parents and two brothers in a happy, Orthodox home. Once the Nazis invaded Poland, the family made a harrowing escape, first to a nearby ghetto, then into hiding under the protection of Righteous Gentiles, and finally to the forests, where partisans took them in.

A sheltered 17-year-old at the time, she was forced to adapt to the rigors of partisan life (the book title comes from an edict by her commander, who changed her name to the less Jewish-sounding Sonia). Orbuch served as a field nurse, tending to wounded partisans who went on dangerous missions to harass and sabotage German soldiers and their Ukrainian collaborators.

“I always heard the question, ‘Why didn’t Jews fight back?’ ” Orbuch says. “I was so upset about it, because some Jews fought back as much as possible. As it turned out, my story is very important.”

One brother died serving the Red army, another on a mission with the partisans. Ultimately, the region was liberated, but Orbuch’s mother succumbed to typhus just as the war was ending. In all, she lost 60 family members.

After the war, she and her father ended up in a displaced persons camp. There she met her husband, Isaac Orbuch, with whom she immigrated to New York, where the couple raised two children. Fate dealt another tragedy when her husband developed early-onset Parkinson’s disease, which eventually claimed his life.

Sitting down with Rosenbaum over a three-year period to recount her story took an understandably emotional toll on Orbuch. “There were times it was hard and painful for her,” Rosenbaum says. “There were numerous times she wept. The emotion she showed reminded me so much how this happened to real people.”

Rosenbaum, who co-founded Berkeley’s Lehrhaus Judaica, has written numerous books on Jewish history, and one other about a Jewish partisan — Joseph Pell of San Francisco. But the story of women who were partisans intrigued him, as they comprised 10 percent of the Eastern European partisan forces.

“I put things in context,” Rosenbaum says. “I had spent many decades studying, teaching and writing [about] the Holocaust and European Jewish history, and it was really all out of books. But to come face-to-face with someone who lived through it put things on a different level.”

These days, Orbuch enjoys telling her story to young people. She remains close with her family, in particular her 20-year-old granddaughter, Eva. A speech Eva gave at a 2007 Yom HaShoah observance, held at San Rafael’s Osher Marin JCC, is included in the book’s appendix. In that speech, she honors her grandmother.

“She’s very proud of me,” Orbuch says. “Sometimes she wonders how I was able to accomplish what I did.”

Though she fought back, and she and her father survived the Holocaust, the toll on Orbuch’s family was devastating. She lives with the loss every day.

“When people ask me, ‘Can you forgive?’ I say I can never forgive. It’s not my place to forgive. I keep telling the children, if you find a way to fight back against anti-Semitism, then fight. Never accept what you see is wrong.”

Sonia Shainwald Orbuch and Fred Rosenbaum will speak at 7 p.m. Wednesday, May 20 at the Osher Marin Jewish Community Center, 200 North San Pedro Road, San Rafael. Free. For information, call (415) 444-8028. For more on Jewish partisans, contact the Jewish Partisan Educational Foundation at www.jewishpartisans.org.

“Here, There Are No Sarahs” by Sonia Shainwald Orbuch and Fred Rosenbaum ($16.95, RDR Magnes Books, 241 pages)