LONDON — Letters in which Albert Einstein openly discusses his girlfriends and moans to his wife how they showered him with “unwanted” affection were made public for the first time yesterday.

The large collection shows the private life of a much younger and good-looking Einstein than the iconic image of the old man with a mane of white hair, talking about his extramarital affairs with his second wife, who reluctantly accepted his philandering.

The letters were released yesterday by the Albert Einstein Archives at the Hebrew University of Jerusalem. Spanning almost 3,500 pages, the correspondence encompasses letters to and from his first and second wives and his two known children between 1912 and 1955 and confirm a more rakish and human image of Einstein that first began to emerge two decades ago with private correspondence and the use of suppressed manuscripts.

Einstein’s dalliances feature in the almost daily letters he wrote to his second wife, Elsa, herself once the subject of his extramarital attentions, and to her daughter, Margot, while away from home. Although Einstein’s wandering eye will not in itself be news, the letters fill in many details to create a much more detailed picture of Einstein.

In 1923, he fell in love with Betty Neumann, the niece of a close friend, Hans Muhsam. Einstein did his utmost to integrate her into his family life. He failed and his parting words to Betty are remarkable and touching: “[I] must seek in the stars what was denied to me on Earth.”

Between the mid-1920s and his immigration to the United States in 1933, he flirted with various women, including a blond Austrian, Margarete Lebach, Estella Katzenellenbogen, the rich owner of a florist business, and Toni Mendel, a wealthy Jewish widow.

They shared the pleasure of sailing, of reading books, of attending concerts, and more with Einstein. The letters suggest there were an additional Toni, an Ethel, and perhaps other women filled some gaps.

Ethel Michanowski, a Berlin socialite and friend of Margot’s, was involved with Einstein in the late 1920s and early 1930s. A letter to his wife Elsa reads: “Mrs M definitely acted according to the best Christian-Jewish ethics: 1) one should do what one enjoys and what won’t harm anyone else; and 2) one should refrain from doing things one does not take delight in and which annoy another person. Because of 1) she came with me, and because of 2) she didn’t tell you a word. Isn’t that irreproachable?”

She went so far as to chase him to England, an archivist at the Einstein Archives, Barbara Wolff, said. In one letter to Margot in 1931, he complained that “Mrs M [Michanowski] followed me [to England], and her chasing me is getting out of control.”

Some conspiracy theorists have argued that Einstein gave his first wife, Mileva Maric, his Nobel Prize money because she had helped to develop his first theory of relativity, when the mainstream view is that the money was for the upbringing of his sons.

But these letters show that he instead invested the most of the money in America, much of which was later lost in the Depression. This caused friction with Mileva, who felt betrayed because he did not deposit the entire sum as agreed, and she repeatedly had to ask him for money. Ultimately, however, he paid her more money than he received with the prize.

The letters for the first time include replies from Einstein’s family, Hanoch Gutfreund, the chairman of the Albert Einstein Worldwide Exhibition at Hebrew University said, adding that it helped to shatter myths that the Nobel Prize-winning scientist was always cold toward his family. “In these letters, he acts with much greater friendship and understanding to Mileva and his sons.”

Einstein’s younger son, Eduard, had just started university studies when he had a nervous breakdown and had to be admitted to hospital. Soon afterward he was diagnosed as schizophrenic. But Einstein found his son’s mental illness difficult to accept, and on more than one occasion expresses the idea that it would have been better if Eduard had not been born.

Einstein became a global superstar with his general theory of relativity. But, in a letter to Elsa in 1921, Einstein admits,”Soon I’ll be fed up with the relativity. Even such a thing fades away when one is too involved with it.”

The collection released yesterday has been in the Einstein Archives at the Hebrew University for many years, but was not made public in accordance with the will of his stepdaughter, Margot, who specified that they not be released until 20 years after her death. She died on July 8, 1986.