Einstein died in 1955, naming Otto Nathan and Helen Dukas co-trustees of his personal papers. The pair was fiercely protective. In 1958, they blocked publication of a book by Hans Albert's wife, Frieda, because it quoted from letters written by Albert, Mileva, and their sons.
More than two decades later, Princeton University Press started work on The Collected Papers of Albert Einstein (CPAE). Nathan stalled the project by disputing the number of editors required. Meanwhile, the papers were being copied because Einstein's will dictated that when Dukas died, all the originals must go to the Hebrew University. She died in 1982 and the CPAE project moved forward again, using the copies.
By 1985, Frieda's book was largely forgotten. Then CPAE editor Robert Schulmann heard about some early "love letters" in the hands of Einstein's relatives in California. He located Evelyn Einstein in Berkeley. She had her mother's unpublished manuscript, but not the letters. The search led to a safety deposit box and a cache of 400 family letters stashed by Evelyn's stepmother, Elizabeth Roboz Einstein. The CPAE delayed publication of Volume 1, so that 51 of the love letters could be included. The book was released in 1987, and the scientific world hummed with Mileva Maric's name. The general public learned of the story in 1992, when the Press printed The Love Letters.