Correspondence, By Ingeborg Bachmann and Paul Celan, trans. Wieland Hoban

Theirs was an unlikely friendship. Or, as they would later wryly comment, an "exemplary" one. He came from that once vibrant centre of Jewish-German culture, Czernowitz, Bukovina, and had survived a Romanian labour camp; both his parents had been killed in a Nazi death camp in Ukraine. She had grown up in the southernmost province of Austria, Carinthia, in relative cultural isolation, and in conflict with her father's National Socialist beliefs and actions.

He, the young Paul Celan, referred to as "the only lyric pendant to Kafka", had written a number of highly regarded, if as yet unpublished, poems, and was in Vienna en route for Paris. She, Ingeborg Bachmann, six years his junior, was a burgeoning poet, seeking her voice and place in the curious place that was the post-war – and post-Auschwitz – Viennese literary scene, while completing her doctoral thesis on Martin Heidegger. Their encounter in spring 1948 was the upbeat to a magnificent, and troubled, meeting of minds that would last a lifetime.

This much-anticipated volume, handsomely published in a fine translation by Calcutta-based Seagull Books, also includes the handful of uneasy letters between Celan and Max Frisch, Bachmann's companion from 1958-1962, and the gracious, searingly moving exchange between Bachmann and Gisèle Lestrange, Celan's wife from 1952. From the opening poem dedicated to Bachmann on her 22nd birthday, "In Egypt", one is in the intimate sphere of two highly intelligent individuals, fascinating and bewildering to the other, who came to epitomise the rigorous contemplation of what was possible in German-language poetry and prose after the Shoah. In almost 200 letters, telegrams, postcards, unsent drafts, poems as love-letters, they tussle with the possibilities and limitations of communication through the written word. Silence and personal darkness have their place. The compromises exacted by life on art, the power and powerlessness of language, fear of the written word, and belief in dialogue through poetry are subjects broached.

Time and circumstances conspired to create absence rather than proximity. After those spring months of 1948 ("my bedroom is a field of poppies"), it was not until 1950 that they lived together – disastrously – in Paris for two months, Bachmann referring to their co-habitation as "Strindberg-esque". The next meeting was at the spring 1952 gathering of the influential post-war literary circle, Gruppe 47. Both were invited to read their work: it was a triumph for her and a catastrophe for him. The reception of "Todesfuge", "Death Fugue", a work Celan regarded as "the only epitaph my mother has", was dismissive; evidence, he surmised, of the unjustly tricky path for the rare bird he had become, a German-Jewish poet.

While personal relations were distanced (him) or despairingly hopeful (her), they continued to converse on professional matters. Bachmann was tireless in her dedication to the careful positioning of his writing and reputation. While working in radio to scrape a living, she fought hard for writing hours, achieving a further breakthrough in 1953 with her collection Borrowed Time.

Both were invited to a symposium in Wuppertal in 1957, and the love affair resumed – with gusto. Now Celan flooded Bachmann with letters, poems, telegrams, addressing her as an equal, recognising her poetic voice at last: "I felt I was drowning in something completely transparent and bright." This period – so verdant, yet impossible to sustain – yielded to a negotiation for "friendship" through the 1960s.

Bachmann was living with Frisch, but remained stalwart in her support of Celan, not least through the Goll affair: those manipulated accusations of plagiarism that toppled him into the mental instability and breakdown that would culminate in his suicide in 1970. To read this correspondence with the relevant poetry to hand confirms the rich content of these letters. Taken together, there seems no doubt that, in each other, Bachmann and Celan did have that precious, nigh-impossible fellow being: a companion "you... for me... sensually and intellectually... the two cannot separate".