The French capital was an attractive prospect for a 23-year-old American writer: cheap francs, legal booze and, on the Left Bank, a distinguished collection of artistic expatriates.

After almost a year in France, Hemingway travelled to Switzerland for a freelance assignment. When Hadley joined him for Christmas, she packed his manuscripts, knowing he would want them. It was a typically thoughtful gesture. But Hadley’s suitcase was stolen at the Gare de Lyon, and she had to tell Hemingway that everything was gone.

“I suppose you heard about the loss of my Juvenilia?” Hemingway wrote to Ezra Pound. “I went up to Paris last week to see what was left and found that Hadley had made the job complet by including all carbons, duplicates etc.” In another letter, to his friend Bill Smith, he lamented: “[E]very thing I’d done for two years … every thing.” It hit him “awful damn hard”.

Three years later, by December 1925, Hemingway had written some of his finest short stories and released three collections (including In Our Time). His first novel, The Sun Also Rises, was in final draft and close to a contract with Scribners, a deal partly facilitated by his satire, The Torrents of Spring.

He was backed by prominent literary figures: Pound, Gertrude Stein, John Dos Passos, Ford Madox Ford, F. Scott Fitzgerald. He’d fathered a son, discovered bullfighting, and created the Paris memories he later evoked in A Moveable Feast.

The Letters of Ernest Hemingway, Volume 2: 1923-1925 covers this crucial time in Hemingway’s life, picking up where Volume 1 left off, after the suitcase theft.

These were the years his apprenticeship ended, when the “tight and hard as goat shit” prose that won him a Nobel Prize (his words, not the Swedish Academy’s) first came to maturity. To have every available letter written by Hemingway in this period is enormously significant. The collection is also a cracking read.

The letters show him as a young writer, struggling for recognition. “I want, like hell, to get published,” he writes to editor Edward O’Brien. “What do you advise?”

Often, his efforts were rejected: “Mr Vance’s letter has made me feel pretty low. Got drunk on the strength of it. “And he describes candidly the challenges confronting a literary career: “… we haven’t got any money anymore I am going to have to quit writing and I never will have a book published”.

Of course, this made success all the sweeter. Hearing that My Old Man would feature in the Best Short Stories of 1923, he wrote: “Your letter couldn’t have had any greater effect if it had been to inform me that I’d just been given 1 million dollars [and] the VC.”

Hemingway sneered at the consciously “literary” and disdained critics as “camp following eunochs of literature”. (In his letters, Hemingway’s prose was not always of Nobel standard, as “eunochs” demonstrates.)

Yet Hemingway was attentive to his own aesthetic: “I’m trying in all my stories to get the feeling of the actual life across – not just to depict life – or criticize it – but to actually make it alive.” He aims to evoke landscape “like Cezanne”, “so you dont remember the words after you read it but actually have the country”. Of the process itself, he says: “I write slowly and with a great deal of difficulty.” Apparently, a hangover helped: “Been souzed everynight … I always work well under the influence of gastric remorse.”

Despite Hemingway’s views about “professional critics”, he valued the feedback of senior literary friends. Indeed, these friendships were integral to Ernest and Hadley’s wider (and wilder) life in Paris. We see Ernest boozing with Fitzgerald and having to wire the latter’s wife, Zelda, when Scott missed a train on a boys’ trip to Lyon.

To Pound, he confided, “JESUS I WAS DRUNK LAST NIGHT”, and for the poet he suffered an opium jar in the face after denying a broom-wielding junkie a debt claimed against his mentor: “He looked at the jar and then threw it at my head saying, ‘You son of a bitch I’ll kill you’.”

The letters record him attending Stein’s salon and Sylvia Beach’s Shakespeare and Co bookshop, as well as Joan Miro’s first show. They also, somewhat incredibly, record him teaching Fitzgerald to box.

It wasn’t all Paris. The Hemingways took regular alpine holidays. From one he wrote to Pound: “Froze my cock at 3,000 meters in long ski tour in blizzard. Damn near passed outwards … Cock is now all right.”

They also visited Pamplona, where Hemingway first saw bullfighting, “the best damn stuff in the world”. One of the Pamplona trips was famously significant for American letters. With Lady Duff Twysden (the model for Brett Ashley in The Sun Also Rises), Harold Loeb (Robert Cohn in the novel), Pat Guthrie (Mike Campbell) and others, the Hemingways celebrated the Fiesta of San Fermin. It was a febrile few days, the “godamdest wild time, and fun you ever saw. Everybody in the town lit [drunk] for a week. bulls racing loose through the streets every morning, dancing and fire works all night.”

Hemingway drew heavily on his friends and their tensions to write The Sun Also Rises, which he started on the train home. The tension was largely over Duff: Hemingway was half in love with her, so was Loeb; Guthrie was her fiance, Hadley was there to watch Hemingway mope, and so was Pauline Pfeiffer, who would become the second Mrs Hemingway. All stuff, as the novel shows, of good drama.

Through letters to his family and friends, Volume 2 presents Hemingway unvarnished: “the author” “who likes to drink and fuck and eat … and write”, but also a man of tenderness and joy who was proud of his son and in love with his wife.

The editors of this project have much to celebrate. Volume 2 is an exceptional collection, magnificently collated and, in Papa’s words, “exciting as hell”.