Josef Mengele’s diaries and notebooks

Josef Mengele’s diaries and notebooks are a record of his exile that joins private writing to close observation of the natural world. Their later recovery and anonymous sale placed these papers within the same posthumous history of concealment and scrutiny that surrounded their author and his family.

Writing and Observation

In exile, Mengele blackened the pages of his diary with tearful poems. Alongside this private writing, he continued studying wildlife and plants, filling notebooks with observations of insects. Cockroaches especially absorbed his attention: he lured them with sugar or meat onto the bathroom floor, examined the blood from injured thoraxes, and sketched their compound eyes. His notes also tracked their physical characteristics, including their six legs and long antennae.

The notebooks’ attention to minute biological detail contrasts with the diary’s tearful tone. Mengele was fascinated by cockroaches’ capacity to change direction rapidly and by their alleged resistance to an atomic bomb. He envied them for being beyond the reach of legal proceedings and penal codes—a striking measure of how his life as a fugitive shaped even his contemplation of insects.

Recovery Amid Family Silence

After his father’s death, Rolf returned to Brazil to retrieve his belongings, correspondence, and notebooks. The recovery took place amid continuing efforts by the family and its associates to keep quiet about their support for the fugitive. Rolf paid Wolfram Bossert for his loyal service and divided the Eldorado bungalow between Bossert and the Stammer family; the Stammers sold their share to Bossert. The two families vowed to keep Uncle Pedro’s death secret, while the wider Günzburg family also maintained its silence. The notebooks thus reappeared not in a public reckoning, but as part of the retrieval of Mengele’s possessions within a network still protecting its secrets.

Auction and Afterlife

In 2011, Mengele’s exile diaries and notebooks were auctioned in the United States for $245,000. Neither seller nor buyer was identified. Their sale gave the papers a documented afterlife as objects of considerable monetary value, while leaving the identities of those who transferred and acquired them undisclosed.