London: The director Richard Attenborough was desperate for a long time to cast Alec Guinness as the Mahatma in his epic film, Gandhi. At other stages, he considered the merits of John Hurt, Albert Finney, Marlon Brando, Dustin Hoffman, Peter Falk (of Columbo fame in the US detective series) and even Peter Sellers.

Ben Kingsley, who was screen-tested on July 25, 1980, at Shepperton Studios near London and won one of the eight Oscars scooped by the film two years later, got the part after everyone else Attenborough had wanted had either rejected his offer or was found to be not quite right for the lead role.

After they had watched the rushes together<>, Attenborough teased Kingsley by making the offhand remark: "Well, I suppose you'd better play it then."

After it had sunk in that he had got the role, Kingsley responded: "I shall be the film's most humble servant."

The details of how the Mahatma's life had moved from concept to movie over a 20-year period are revealed in the Attenborough archives, now lodged with the University of Sussex.

Initially, Attenborough wanted a big name actor from the West to play Gandhi because he wanted his film to be a commercial success. In those days, it was not considered such a crime for white actors to "brown up" but later Attenborough realised that Gandhi had to be played by an Indian.

At first, Attenborough did not realise Kingsley was part-Indian. Kingsley had been born Krishna Pandit Bhanji, son of Rahimtulla Harji Bhanji (1914-1968), a Gujarati Muslim from Kenya, and Anna Lyna Mary Goodman, a Jewish Englishwoman.

Kingsley had assumed a new stage name because he had discovered that as Bhanji, he was not getting any work. Now a distinguished knight of the realm as Sir Ben Kingsley, the 74-year-old actor has never gone out of his way to highlight his Indian origins.

It now seems that Attenborough was pointed in the direction of Kingsley by his son, Michael Attenborough, a theatre director.

Attenborough's encounter with the Mahatma began in 1962 when an Indian, Motilal Kothari, recommended Louis Fischer's biography of Gandhi to him. Kothari, a civil servant, was then working at the Indian high commission in London.

Attenborough had never been to India yet, knew little about Gandhi and had certainly no ambitions about directing a film, which is what Kothari had suggested. But a seed was planted after he read the biography. Over the next 20 years, the germ of an idea became an obsession.

"For years, Attenborough would talk to anyone who would listen about the Gandhi project; one of those sceptical listeners was his friend John Briley, the Detroit-born screenwriter who, years later, would write the eventual script," according to The Daily Telegraph, London.

Briley was not encouraging because he wondered who "would want to pay to see a film about an old man who sat on a rug in a loincloth and spouted words about peace and passive resistance".

"Richard Attenborough died in 2014. His archive at Sussex University, newly and devotedly catalogued, fills 262ft of shelves. Within that, there are 70 boxes of material relating to Gandhi," The Daily Telegraph writes.

"And within those 70 boxes, perhaps the most striking story - the most apposite dilemma, in the eyes of the 2018 reader - is the long-running attempt to cast an actor to play Gandhi himself."

Revealed for the first time are the contents of the letters Attenborough wrote and received as he tried to get his apparently hopeless project off the ground. "My dear Dick," Attenborough's friend Dirk Bogarde wrote to him at the end of October 1980, "the only thing which is of paramount importance... is your actor. He has a very, very difficult task before him, and your film can fall, or rise to great heights, merely on the shoulders of this one man.

"I don't recall, off hand anyway, a role which demanded so much and which had to 'give' so much. He must stand for India itself! Golly!"

Guinness had written to Attenborough directly in October 1963: "I'm too old too old too old too grey-eyed too heavy and just plain too old."

Attenborough persevered. The film would focus on Gandhi as an old man, he argued, so really age was not a factor. Guinness stood firm. "Incidentally," he added, "this is the fourth time I've been asked - no, maybe fifth - to play Gandhi."

But there was another issue. Guinness raised it first, in a letter to Attenborough dated April 11, 1963: "Gandhi should be played by a Hindu."

And a few months later, he repeated the idea, with a prescient addition: "I still think you need an Indian - but this may well be an English name. Or even a no name."

Guinness finally declined the role of Gandhi on February 1964. In acknowledging his decision, Attenborough replied that it was not only a great disappointment to him, but would "also disappoint Pandit Nehru and Indira Gandhi", both of whom had, on his last trip to India, "reaffirmed their desire that you should play Gandhiji".

Just a couple of months before Lord Mountbatten's assassination, the former Viceroy of India wrote to Morarji Desai on June 26, 1979, with a letter of introduction for Attenborough.

But the path was cleared by Indira Gandhi, who returned as Prime Minister in 1980. Attenborough had already seen her in London, introduced by Swraj Paul.

"Some of the casting options in the Gandhi files make for comical reading. Albert Finney turned down the part, in rather gruff terms," writes Independent.ie. "Marlon Brando, fresh from playing the - bald, it's true, but - monstrously large Colonel Kurtz in Apocalypse Now, was proposed for the role of the starving leader. Dustin Hoffman ditto, as well as Al Pacino. Peter Falk - aka Columbo - came up, and so did, in the words of Attenborough, 'Peter Sellers (bless him)'."

"It may be unfair to laugh at these suggestions," The Daily Telegraph comments. "On the other hand, each of them conjures such a radically different Gandhi that to imagine them in the role is to create a mental comic strip of improbable casting - Michael Corleone as Gandhi, anyone? Lenny Bruce? Inspector Clouseau?"