Lindbergh's Double Life

Their mother told them he was a famous writer on a clandestine mission and that they should never talk about him to anyone. He was listed as unknown on their birth certificates. But they had no idea he was such a famous person.

"We were shocked," he said. "But in spite of that, the important thing was still the person in my memories, the warm, tolerant man who tried to explain things to us and took care of us."

The letters to his mother showed a caring side of the pilot, not often portrayed, Hesshaimer added.

"Most of the letters are not love letters," he said. "But they are very warm and the important thing for us is that they show us he really liked us."

The Letters

"Dear Brigitte, my strength is leaving me every day," a letter from a dying Lindbergh in a New York hospital read. "It is very difficult just to write -- all I can send to you and the children is my love."

Dyrk Hesshaimer and his siblings read 150 letters from over almost two decades, and the last was a goodbye, a promise of continued financial support and an admonition to continue the secrecy: "Keep the secret."

The letters, found in garbage bags by Astrid Bouteuil confirmed what she already suspected after she discovered a magazine with an article and picture of her father inside. Excerpts of the letters are published in the new biography.

Other letters give insight into the relationship as well. One 1958 letter responds to the news of Brigitte's pregnancy.

"The news you send is wonderful, and I am tremendously happy about it," the letter reads. "I just wish I could be there with you now… still, there are bound to be hurt feelings, as there have been (with the other lovers)."

At first they held on to the secret until their mother died, four years ago. Then they contacted the American Lindbergh children, confirmed the paternity with DNA testing and decided to go public.

"There is nothing to be ashamed of," Dyrk Hesshaimer said. "We wanted to stop the secrecy. It is important for the next generation -- they can be proud of their grandfather."

And last year, Reece Morrow Lindbergh, the youngest American daughter of Lindbergh and president of the Charles A. Lindbergh and Ann Morrow Lindbergh Foundation, visited all seven of her siblings in Europe.

"They seem to be very accepting about each other," said Berg, who has met some of Lindbergh's children. "It is a hard thing to find out that your father wasn't the man you thought he was."