The private life of arguably the greatest scientist of the century has, despite his fame, remained a closed book. Years of censorship have suppressed private letters showing his philandering nature and dismal failure as husband and father.
A book to be published later this year, however, aims to explode the almost beatified image of the scientist whose theories of relativity were quickly deemed the most momentous product of human thought.
'Perhaps it should be seen as a marvellous joke on humanity that such strength and such weakness, such wisdom and such obtuseness, could be combined in one man,' write Roger Highfield and Paul Carter, the authors of The Private Lives of Albert Einstein.
They describe how Einstein conceived an illegitimate daughter by Mileva Maric, whom he later married. The baby girl was soon 'sent away' for adoption.
They explain how Einstein's marriage to Mileva collapsed after he had started an affair with his cousin, Elsa, who became his second wife.
Einstein's two sons by Mileva lived under his domineering influence.
The youngest, Eduard, declined into mental illness and spent the last years of his life in a psychiatric hospital, unvisited by his father.
The great man's womanising was to undermine his second marriage and cause his doctor, Janos Plesch - one of the last people to see him alive - to suggest that his death was brought on by advanced syphilis.
'Why shouldn't a healthy and beautiful man have had bad luck in his youthful daredevil days and contracted a lues (venereal disease)?' Plesch wrote in 1955, the year of Einstein's death.
Einstein's philandering became part of the private folklore of the family, say Highfield and Carter: 'Yet his love for women's company often seem combined with a scorn for their intellect and character that bordered on misogyny.'
His marriage to Mileva - between 1903 and 1919 - covered the most important period of his life, when he formulated his special and general theories of relativity.
She is believed to have provided more than emotional support, being an accomplished physicist herself.
She later claimed to be the unrecognised author of relativity and perhaps Einstein recognised her contribution by giving her all his Nobel Prize money as a divorce settlement.
The authors claim that Einstein himself took great care to 'cover his tracks', and a procession of personal secretaries, relatives and keepers of the Einstein 'flame' continued the deception.
Original documents, mostly private letters that could have told the true story of the scientist, have disappeared. 'The most plausible explanation is that the originals were deliberately destroyed . . . but it is almost impossible to dip into Einstein's non- scientific writings without producing hints of his personal troubles,' the authors say.
The Private Lives of Albert Einstein, by Roger Highfield and Paul Carter (Faber and Faber pounds 14.99), is to be published in September.