In 1988, Paul Schwarzbart was invited to a reunion of Jewish children who were hidden at the Home Reine Elizabeth, a Catholic boys school in the Belgian countryside. His immediate reaction was to wonder: “Who was I going to have the reunion with? Myself?”

But when he arrived at the school, he discovered to his astonishment that of the 125 boys who had been there during the war, well over 60 were Jewish. None, including 6- or 7-year-olds, had breathed a word of their identities; none knew that any of the others was a Jew. Even those who were brothers kept their silence, not revealing their relationships to the others.

Of the Holocaust’s countless stories, this is surely one of the most uplifting. It is recounted in Schwarzbart’s memoir, “Breaking the Silence: Reminiscences of a Hidden Child.”

Marie and Emile Tacquet ran the school, and along with their staff of teachers and counselors they exhibited extraordinary heroism. So did the Belgian Committee for the Rescue of Jews, which maintained an intricate system of ledgers, hidden in four different locations to keep the Nazis from finding where the Jews were hidden.

On his trip back to Belgium, Schwarzbart was able to see these ledgers in the Belgian archives and to find his own name and code number there. Until then, all he knew of the Belgian underground was the mysterious young man who appeared at his mother’s door in Brussels in 1943, who said she had to give up her 10-year-old son immediately.

Schwarzbart’s mother becomes the hero of this stirring book; first, by making the snap decision to entrust her son to the young Belgian résistant. Separated for more than a year, mother and son were reunited after the liberation of Belgium, ultimately making their way to San Francisco.

But her heroism really began in May 1940, when the Belgian police arrested her husband after the German invasion of the lowlands. Belgium was at war with Germany, and Schwarzbart’s father, an Austrian citizen, was declared an enemy alien; even though as a Jew, he had last had sympathy with Germany. Interned in Vichy, France, he was later deported to Gross-Rosen, survived a death march to Buchenwald in 1945, but died there shortly before liberation.

With no knowledge of her husband’s fate, Schwarzbart’s mother resourcefully managed to keep herself and her son alive as foreigners in wartime Brussels. She did so with the help of a number of heroic non-Jewish Belgians, including Schwarzbart’s elementary school teacher.

In this story full of love and altruism, the most traumatic moment was the arrest of Schwarzbart’s father; in that moment, Schwarzbart really begins to tell his story. The worst trauma for many Holocaust survivors seems to have been not the violence and brutality they witnessed — which Paul Schwarzbart was spared — but the agony of separation when a loved one was torn away and dispatched to an uncertain fate.

Though Schwarzbart titled his memoir “Breaking the Silence,” he broke his silence many years before publishing this book. Filmmaker Ken Swartz documented Schwarzbart’s trip to Belgium in 1988, and Schwarzbart, who lives in Marin, has been an active and effective speaker at schools throughout the Bay Area.

I teach a yearly course on the Holocaust at U.C. Davis, where I am professor of Jewish history, to a class numbering around 150. Last year I invited Paul Schwarzbart to speak. Many students called it the most memorable session of the quarter.

Schwarzbart told his story as well as he has written it in his memoir. He joked and he cried; my class laughed and cried with him (after class, one student came up and asked if it was OK to give him a hug). Although over 70, he still exudes the charm of a child and it is not hard to imagine him as a 10-year-old boy in a Belgian Catholic school.

For those who have not been privileged to hear Paul Schwarzbart, this moving memoir provides a next-best experience.

“Breaking the Silence: Reminiscences of a Hidden Child” by Paul A. Schwarzbart (144 pages, Authorhouse, $15.50).