Sixty years ago next week, the actor Sir Donald Sinden made his stage debut at the Theatre Royal in Brighton.

The 18-year-old apprentice joiner was nervous as he prepared for his performance.

Little did he realise as he walked out under into the blazing spotlights for the first time that he was taking the opening step in an acting career which would span six decades.

Sir Donald Sinden still recalls the occasion perfectly. It was the opening night of Gerald Savoury's play George and Margaret on January 26, 1942.

It was a minor role in a little-remembered comedy, but it was a moment which has remained etched on the 78-year-old actor's mind.

Sir Donald said: "It was pretty nerve-wracking but I didn't make any mistakes. It was my first experience of the incredible camaraderie of the professional theatre. It felt like I was entering a family of friends."

Ever since that day January 26 has become much like a birthday to Sir Donald, who celebrates the date annually.

He added: "Every year I remember it as the occasion of my very first professional performance. It's always stuck in my mind whereas I can't recall the second performance at all.

"I suppose it's just as a runner will always remember the first time they run a mile under four minutes. You may run quicker times in the following years but the first time is always the one you remember best."

The curious thing about the beginning of Sir Donald's career was how easily it may not have happened.

As a youngster growing up in Ditchling he had no inclination to act and fell into the theatrical world by chance.

The year before his performance at the Theatre Royal the teenager was asked to take over his cousin Jack's role in an amateur production at Brighton Little Theatre.

Sir Donald recalled: "Jack had been called up by the RAF in the middle of rehearsals. I was asked to take his place and thought : 'Why not?' The fact is if it hadn't have been for him I would never have even thought about it."

He enjoyed the experience and helped out with two further plays at the theatre over the next few months.

But he did not think seriously about taking up acting until he was approached by Charles F Smith, an impresario who ran a wartime touring company known as Mobile Entertainments Southern Area (MESA).

Mr Smith had seen one of Sir Donald's performances and invited him to join the company which was putting on the Gerald Savoury production at the Theatre Royal. Sir Donald was offered a debut role as the adolescent Dudley.

He said: "It was a pretty frightening experience but enormous fun. I was working with professional actors for the first time in my life and I was totally green. Even so they were wonderfully patient and treated me as well as I have been before or since."

It was during his time with the cast of George and Margaret that Sir Donald's attitude towards acting underwent a transformation.

He said: "I learnt an incredible amount from that first performance. They taught me a huge amount about timing which has stood me in a good stead ever since. They were a group of remarkable people.

"I never thought it was the start of a career until I joined the professional stage. I think it entered my mind about halfway through rehearsals that this was what I wanted to do for the rest of my life."

He was deemed medically unfit to enter the Navy due to asthma, an ironic twist in view of his later role as a naval officer in the Cruel Sea which made him famous.

Sir Donald was among those who helped the war effort at home. For the next three years he held down two jobs: as a joiner by day and an actor by night.

He never told his workmates of his double life and led a schizophrenic existence, using two accents depending on whether he was with the lads at work or actors on stage.

He was encouraged to take up acting as a career and became a full-time professional in 1944. The son of a chemist had taken another step on the path to becoming one of Britain's great actors.

In the 60 years since that first role at the Theatre Royal Sir Donald has given thousands of performances in a range of plays, films and on television.

When asked how many productions he has appeared in during his career, Sir Donald chuckled as he recalled a remark he recently overheard on the radio.

He said: "One man was ridiculing another for stating the obvious. The line he used was: 'You might as well ask Donald Sinden if he's been in 100 plays'. In fact I lost count a few years ago but it's probably more than 150."

After the war Sir Donald continued working in theatre as well as picking up a few film roles. Then came his first big break in movies with the role as Lockhart in The Cruel Sea.

He eventually spent eight years with the Rank Organisation during the Fifties playing a succession of suave, leading men and handsome naval officers. Another screen credit was John Ford's Mogambo in which he starred alongside Clark Gable and Ava Gardner.

Unfazed by their star pretensions, Sir Donald thought nothing of putting his Hollywood colleagues in their place. He once gave a lecture to Gardner for refusing to join them for dinner and then scolded her for putting her feet on a chair.

In 1960 the British film industry collapsed and Sir Donald faced unemployment for the first time in two decades. He turned back to the theatre and joined the Royal Shakespeare Company, a decision which led to some of his finest work.

Sir Donald said: "Playing Shakespeare has been the most wonderful experience. There is the simple joy of just saying the words. I have so many happy memories but my work with the Royal Shakespeare Company was really special and is what I am most proud of."

Among the most enjoyable performances of his career, he lists his 1974 role as Dr Stockmann in Henrich Ibsen's play Enemy of the People at Chichester.

He recalled: "It was a monumental part. For the first time I had a character who was exactly like me. His attitudes were all my attitudes. When I was doing that I thought: 'By golly, I'm ready to play King Lear'. Sure enough the following year I was offered that very part."

Of the most embarrassing moments in his career, he recalled a play at the Queen's Theatre in London in 1960 which was pulled off after just three performances.

He said: "I remember it was called Joie de Vivre and the critics did not like it at all. They thought it was terribly old-fashioned.

"I remember I was disappointed but I didn't feel personally responsible. And I had to agree: it was.

He said: "As a teenager my voice was mouse-coloured and weak. It did not have timbre and for theatre work I realised I needed to expand and deepen it."

Like all great actors Sir Donald has no plans to retire. Next month he will go on a lecture tour of universities throughout the country to talk about his acting career.

He also has some forthcoming radio and television commitments.

He said: "It's enthusiasm that keeps me going. And adrenaline. Every time I perform I get the same buzz I've always done. I guess it's just in my blood and always will be. In any case I've never heard of an actor retiring."

Far from resting on his laurels he still has at least one more ambition.

He explained: "In an interview 25 years ago I said I had done most things you could achieve in my profession except ballet and opera.

"The very next day I was offered a speaking part with the English National Opera. So I still have the ballet to do. Perhaps one day."

He has no specific plans to mark his 60th anniversary in the business other than to spend the day at his home near Rye with his wife Diana, whom he married in 1948.

Sir Donald said: "I'm not planning to do anything special. I'll probably just celebrate it in my own way with a glass of bubbly or something. To be honest, I don't really like champagne, so it will have to be a glass of whisky instead.

"It's nice to be celebrating an anniversary with the Queen this year although I can claim mine is a Diamond compared to her golden jubilee. After all, I've been doing the job ten years longer."