Tragic drama was played out in the rehearsal room, and in real life, when Southend Shakespeare Company embarked on their production of King Lear, which opens on Tuesday at the Palace Theatre.

The role of Lear, the once great king who disintegrates into senility and death, taking much of his world with him, has become a metaphor for the part that every older male actor aspires to. It stands unchallenged as the peak role in all drama. “The role of Lear is the touchstone that, time and again, has made great actors out of those who before were merely very good,” wrote one critic.

The play’s director, Malcolm Toll, had little hesitation in casting veteran SSC actor Roy Foster in the title role. Roy was a key presence in SSC for four decades.

Jim Carter, SSC’s chairman, says: “He was a towering voice and figure, and very much an elder statesman of Southend Shakespeare Company.”

Roy had already played the role once before. “But he wanted another stab at it,” says Malcolm. “I think he thought with the extra experience of life he had acquired since the previous time, he could bring new dimensions to the role.”

Roy prepared himself for the demands of the role, physical as well as mental, with dedication. Malcolm says: “I found out after he died that he actually bought a pair of weights, so that he could build up his physical stamina for the part.”

Yet within weeks of starting rehearsals in the part of the doomed king, Roy himself was dead, the victim of fast onset cancer.

Roy attended early rehearsal sessions, but was clearly in rapid decline.

Malcolm says: “It was terrible for everyone to see a man who had been so active reduced to this state.

“On the last night, he could hardly get off a chair. The next day he rang me to say that he would have to pull out of the production.”

Just weeks later, Roy died in his sleep.

SSC members grieved for their old friend and colleague, as well as his widow, Beryl, also a long-term member of the group.

But they were also faced with the practical problem of finding a replacement.

Actors made of the right stuff to take on the huge burden of King Lear are not two a penny.

However, Malcolm and Jim believed that one SSC actor, Keith Chanter, had “what it took”. Keith had made a strong impact in his previous Shakespearian role, as Brutus in Julius Caesar.

Malcolm says: “Keith wasn’t involved in King Lear originally, though he had auditioned for the part of Gloucester.

“But his approach was ‘How can you not take the chance to play Lear?’ ”

While throwing himself into the demands of playing the old king, Keith is quick to honour his predecessor.

He says: “Roy was a much loved member of the company and a fine actor. I hope that my performance will be seen as a tribute to him.”

When Malcolm embarked on King Lear, he had no inkling of the sad storyline to come.

He says: “I was slightly surprised when Roy auditioned for the part, because I knew he had done it before and was aware of the stresses involved.”

Malcolm’s main reason for wanting to stage Lear was simply a practical one. He says: “I appeared once in Lear, as the Duke of Kent, and I was aware that it has a great range of strong parts, including parts for women.

“That’s not always the case. If you take a play like, say, Richard III, it has just one domineering character, and lots of bit parts that get pretty well overwhelmed by the title role.”

Among this strong cast of characters, Megan Terry plays Lear’s loving daughter Cordelia, with Madeleine Ayres and Jo Seymour as her black-hearted sisters, Goneril and Regan.

John Newell is the blinded Gloucester, whose journey into darkness parallels that of Lear, while Ian Downie plays the key role of the Fool, ironically the wisest figure in the story. Jim Carter is the faithful Kent, with SSC newcomer Nick Edgeworth as Edgar, the king in waiting.

Malcolm is staging the play in-the-round, increasing the impact and sense of immediacy. He has gone for a plain approach, without embellishments or gimmicks. He says: “I’ve looked for simplicity, letting the words do the work.”

Four centuries after it was written, King Lear remains as relevant as ever.

Malcolm says: “It is a story about a king who hands over power, and the effects that the loss of power can have on an individual.

“I was constantly aware of the real-life parallels with Margaret Thatcher, and how she went into decline once she had been ousted from power.”

King Lear is always a tough experience for actors and directors, and SSC has faced a special trauma.

But among the many dark ghosts which hug the shadows of Shakespeare’s darkest tragedy, there will be one smiling figure.

“We’re all confident about one thing,” says Malcolm. “This production has Roy’s blessing.”

King Lear Palace Theatre (Dixon Studio). Westcliff Tuesday, April 22 to Saturday, April 26.

Nightly at 7.45pm, matinee on the Saturday at 2.30pm Tickets, £11 (conc £9.50) from southendtheatres.org.uk or 01702 351135