It is not something one would necessarily expect.

A new translation of the Hanuman Chalisa — the popular devotional poem written by the sage Tulsidas in the 16th century — is always welcome.

What’s surprising is that this translation is by Vikram Seth, the best-selling, award-winning author of novels about passion, loss and life on the fringes; novels such as A Suitable Boy (1993) and An Equal Music (1999).

In many ways, this version of the Chalisa (a hymn in 40 verses) says a lot about its reclusive translator.

First, it has nothing to do with any Hindutva sentiment. In a short introduction to the book, Seth, 72, writes about “fighting the chauvinism and intolerance to which this and many other well-beloved religious texts and rituals have been put”.

Second, the translation is a considerable technical achievement. Seth, like many Hindus, can recite the Hanuman Chalisa from memory, and has sought to preserve the rhythm and meter of the original Hindustani / Awadhi couplets.

That is not easy to do. But, as Seth always says, he is a poet first. His technical skill as a poet first brought him to international attention, with The Golden Gate (1986), which was written entirely in verse. And he has published more books of poetry than novels.

Third, there is the reason he did the translation. Bhaskar, a character in A Suitable Boy, plays a monkey warrior in the Ram Leela when he is a child and then, when he is in his 50s, goes on to fight against religious intolerance.

Most writers would have been content to create the character of Bhaskar and move on, but because Seth researches every detail of his characters and the times in which they live, he began studying the Hanuman Chalisa. The fascination continued long after A Suitable Boy was published, and then, 10 years ago, Seth embarked on this translation.

He never intended to publish it, he says, but was persuaded last year to put it out as a book.

***

I first met Seth in the late-1980s, when he was working on A Suitable Boy. The Golden Gate had been a huge success but there was nothing to suggest that his next work would have the scale it did, at about 1,400 pages long, taking its characters through decades of Indian life and history.

The author devoted years to writing it. He wrote some of it in a room in the large house that his mother, Leila Seth, occupied as a judge at the Delhi high court, and I remember seeing the huge board he put up on one wall, bearing the names of his characters and their progress through the decades.

I marvelled at his dedication, but none of us had any idea the book would be a huge international best-seller, that British and American reviewers would compare Seth to Tolstoy, or that this second work would end up on lists of the greatest novels of the 20th century.

The obsessive attention to detail that led Seth to research the Hanuman Chalisa extended to everything else in the book. He researched cities and time periods, even verifying that every word or idiom uttered by his characters in the novel reflected how people talked in those places, at those times. It is no wonder it took him a decade to finish it.

The success of A Suitable Boy led to demand for a second novel, but Seth resisted. He had been exhausted by the publicity campaign around it. That’s the part of being a writer that he likes least, he says.

He wanted to do other things and move away from the world of celebrity that he had been drawn into.

So he wrote a libretto for an opera, and wrote novels that hardly anyone has seen, because he will not publish them. On the bookshelves of the room where he now does much of his writing, in Noida, are bound manuscripts that he says “just don’t seem ready”.

He did go on to publish volumes of poetry, his true passion, and when a second novel was published, it was very different from the first. An Equal Music is a love story set in Europe. It became a best-seller, got good reviews and sealed his reputation as a great writer. And, as always, his attention to detail led to side-projects.

While writing An Equal Music, about the love between a violinist and a pianist, Seth became fascinated by the classical compositions mentioned in the book, and collaborated with the violinist Philippe Honore on a double CD of the music in the novel.

In the 25 years since An Equal Music, there has been Two Lives (2005), a non-fiction work about his great-uncle Shanti Seth and his great-aunt, the German-Jewish Hennerle Caro. There has been more poetry, and the hit TV adaptation of A Suitable Boy, directed by Mira Nair. But there has been no sign of A Suitable Girl, the sequel announced in 2009.

Seth is reluctant to say how much of the novel has been written, or to talk about it at all. But the house he shares with his aunt in Noida is filled with reference material. Presumably, the 1965 war with Pakistan features prominently, because Seth maintains files on every aspect of that conflict.

***

To see Seth in the room where he writes, often under a blue duvet, seated on a bed beneath towering shelves of neatly organised books and clippings, is almost to look into his mind.

Everything here is tidily organised, the shelves are classified by subject.

There is no board with the names of the characters on it this time, because they have all migrated to the inside of his head. He treats his characters as though they are real people. Once he has created them, they take over and lead their own lives, he says, often surprising their creator. It happened with A Suitable Boy, and he had to go back and rewrite the first section, because he hadn’t expected them to behave as they eventually did.

Though Seth lives a full life, with friends, loving siblings and an aunt he dotes on, there is still something of the hermit about him. He spends much of his time with his characters, his notes and files.

He has little interest in money: he has returned, a number of times, the huge advances he got for A Suitable Girl. He has simplified his life, he says, so that he has few needs and no large financial requirements. And he seems happier for it.

Perhaps it is as it says in his translation of the Hanuman Chalisa:

“All the world’s tasks, so confused and contorted /

Thanks to your grace, are untangled and sorted.”