Henry Metelmann is a remarkable individual. As a young man Henry, now aged 81, enthusiastically supported Adolf Hitler and took part in Operation Barbarossa, the German invasion of the Soviet Union in 1941. The suffering he saw on the Eastern Front and the pain of defeat opened his eyes to the evil of Nazism and made him question what he was fighting for.

Now Henry, who has lived in England since 1948, is a peace campaigner keen to ensure the lessons of the past are not forgotten. He sees frightening parallels between the invasion of Russia and the US-led invasion of Iraq last year.

Godalming in Surrey is an unlikely place in which to find a man who served in the 22nd Panzer Division at the Battle of Stalingrad.

Henry Metelmann's sun-dappled, flower-filled garden seems a million miles from that terrible slaughter.

His stories are ghastly but compelling. They are told by a fundamentally decent man who found himself compelled to act as a tool for one of the most hideous regimes in history.

Born in 1922, Henry was just ten when Hitler came to power. He was born in a working class district of a town near Hamburg, his father a railwayman and a Socialist, his mother a Christian. Yet Henry admits to being seduced by the allure of the Nazis - the flags, the uniforms, the speeches, the cameraderie, the promises of victory.

And, yes, he admits, detesting Jews. "I was brought up in an ideology that hated Jews. The young people had it drummed into them. Now I know it was wrong."

He could not wait to join the Wehrmacht, keen to realise dreams of glory in much the same way as thousands of young Englishmen marched off to war in August 1914 thinking they would be home by Christmas.

His views changed when, as a panzerjager (tank driver), he saw the reality, particularly the suffering of innocent people.

The memories and guilt never go away.

"I saw children killed. Their mothers screaming," he said.

He killed in cold blood. "Once I was driving a Panzer over a bridge and there was a wounded Russian in the way. I stopped. The officer said 'drive on'. I drove on - over the man.

"I was following orders but at the Nuremburg trials that was no defence."

Henry was awarded the Iron Cross and needs persuading to show it and others awarded for his roles in the Crimean campaign and 25 Panzer attacks.

"I'm not proud of them. I did not do anything heroic. I was just a soldier. I was grovelling around in the muck of history. The war was a disaster, a catastrophe."

It was only while a prisoner in the USA that he heard about the Holocaust. "At first I couldn't believe it. I saw photos in magazines and realised they were real and not fakes.

"Germany was still my country. It was hard to swallow that I had been part of that criminal action against humanity, that I had fought for it."

In his book Through Hell for Hitler (Spellmount Books, £12.99) he writes: "The feeling of guilt for what in a collective way I have done to others, especially the people of Russia, lies very heavily on me.

"Coming to the evening of my life, I sometimes wonder what it has been - a drama, a tragedy, a crime or a comedy. I cannot be quite sure.

"I have regrets for the suffering I have caused others, but no complaints about what others have done to me."