A wartime promise has turned into a very special 100th birthday celebration for a former British Army officer now living near Newcastle.

On Saturday, Doug Cunningham celebrated his centenary surrounded by 100 local women, after promising his troops he would host a big party if he lived that long.

He was an officer stationed in India at the outbreak of World War II.

As they prepared for battle, he realised he needed to know more about the men he was working with.

Doug says using his brain and not watching too much TV has been the secret to a good life. ( ABC News: Liz Farquhar )

"I had a troop of soldiers and I wanted to know what they were thinking so that if I was caught in a queer situation, I knew I could depend on them," he said.

"I said to them, I want you to talk to me about what you're going to do when the war ends. They said, 'Sir, it's just started!'

"I said, 'Well, it's got to end sometime'.

"One of them said 'I want to get married and have 10 children', one wanted to go to university, they all had different things they wanted to do.

"Then one chap at the back of the hall stood up and said, 'excuse me sir, what do you want to do when the war ends?'

"I sat back in my chair and said, 'Well, I hope I can live to be 100 and I want 100 girls at that do.'

"Well you know, that started the men, shrieking and whistling and laughing, because can you imagine what it feels like to a soldier — a man they knew with 100 girls — that's absolutely fabulous."

Chance conversation made wartime wish a reality

Mr Cunningham survived the war and eventually moved to Australia where he and his wife worked for many years at the Sydney Morning Herald newspaper.

When they retired they moved north to Swansea on the shores of Lake Macquarie, and although his wife died many years ago, he still cherishes her every day.

Women from Mr Cunningham's local supermarket organised the party. ( ABC News: Liz Farquhar )

It was a chance conversation with a check-out operator at his local supermarket that made his wartime wish a reality.

"One of the girls spoke to me one day and said, 'How old are you?'

"And I told her, and she said 'You'll soon be 100' and I said 'Yes, and I hope 100 girls come to the party'.

"And the girls just took that, and said let's see if we can find 100 girls interested in having a party, and that's how it started."

After 100 years, Doug Cunningham has a simple philosophy for living well.

"Enjoy life, use your brain, don't look at TV too often! Just go out and meet people, that's all it is, meeting people and discussing things with them," he said.

And the secret to his long life? Doug suspects his longevity is inherited.

"My mother lived to be 104 and my grandmother to 99," he said.

"I always felt there must be something in their genes that they've passed down."

Doug officially turns 100 on February 23.