Beginning in 1941, the Nazis introduced systematic tattooing of prisoner identification numbers at Auschwitz-Birkenau concentration camp — the only camp to use this practice — as part of the bureaucratic machinery of the Holocaust. Prisoners had numbers tattooed on their left forearms, reducing them to a catalogue entry in the system of industrial extermination. This perversion of the body's capacity to bear meaning — transforming persons into numbered objects — became one of the defining atrocities of the twentieth century and a central image in Holocaust memory.

The Auschwitz tattoo is one of the most powerful and contested images in twentieth-century literature and poetry. Paul Celan, Primo Levi (who bore the number 174517), Tadeusz Różewicz, and Nelly Sachs all engaged — directly or obliquely — with the tattooed number as a figure for the dehumanisation of the Holocaust. The tattoo number appears in Sylvia Plath's controversial 'Lady Lazarus' and in countless poems of witness and testimony, becoming a defining challenge for post-Holocaust poetics about the limits of language in the face of atrocity.