At 92 years old, Leon Greenman's has a forceful voice and a sharp mind - an amazing example of a man his age, and miraculous for someone who endured slave labour under the Nazis and survived five concentration camps.
His testimony, delivered with vitality and candour, about the horrors of Hitler's death camps, has been his life's work for almost 60 years.
Thousands have heard his story, which is all the more incredible because he, his wife, Esther, and baby son, Barney, were British citizens living in Rotterdam in 1942 when the Nazis came to round up Jews.
Mr Greenman, whose tattooed forearm number 98288 featured in the recent teacher recruitment advert "Those who can, teach", is quick to brush aside any suggestion of slowing down or reducing his lecture commitments, which average more than one a week. On top of his hectic speaking schedule, he is the subject of a personal one-man exhibition at the Jewish Museum in Finchley, north London, where he speaks to visitors most Sundays.
His story is one of extreme endurance - he survived the Dutch camp at Westerbork, then Auschwitz, Birkenau, Monowitz and, finally, after the appalling "death marches", Buchenwald, from where he was liberated by the Americans on April 11, 1945. He had spent three years hoping to see his wife and two-year-old son, not knowing they had been gassed shortly after arriving at Birkenau. The collection at Finchley includes Mr Greenman's camp uniform, Esther's wedding dress, some baby clothes and possessions.
This survivor is too much in demand to slow down, and he thanks God for giving him the strength to continue his work, which, he says, is more important than ever. He describes the moment 60 years ago when he vowed to tell the story of the Holocaust. It was in Birkenau in 1943 when he witnessed a guard beat a man to a pulp. "That frightened me; handling and beating was the way of the camp. We prisoners went to bed that night in wooden bunks, afraid, and I prayed not to be beaten. I made a promise to God then that if he could set me free from the camp I would go out and tell the world."
When he returned to England he began to tell his story; then someone suggested he go into schools. "And I have been doing this since 1946. I never get tired of talking about the Holocaust."
Leon's diary is full. In one typical week, he spends Monday making travel arrangements. On Tuesday he travels from London to East Anglia to give two talks - one to a group of local councillors, another to a 100-strong public meeting. On Wednesday he goes home to rest. The next day he is driven to a school in Bedfordshire to give a midday talk to 125 children, followed by an evening address to 200 adults at the same venue. On Friday he travels to the north-west to give two more 90-minute lectures; he arrives home in the early hours of Saturday. Not bad going for a 92-year-old. Some lectures are for the Anti Nazi League, of which he is a member. (In July 2001 in Oldham, where the British National Party had been active, a meeting he was to address was cancelled by the authorities on grounds of public safety.) At the Jewish Museum in Finchley, Mr Greenman gives talks to groups of between 50 and 100 children. "Speaking the truth is easy," he says. "Just one lie, and my work is worthless. I want the world to know that racism is bad and shouldn't happen. It is easy to vote for the wrong people because people don't know the dangers of racism and fascism."
People discover Mr Greenman's story all the time; last year a Dutch film crew made a documentary about his life based on his book, An Englishman at Auschwitz. I came across his story back in February this year while travelling home late from the March for Peace in London's Hyde Park. On an unlit coach filled with dozing marchers a small leaflet was handed to me which I read by the dim light of streetlights as the coach passed by. And in the intervals of darkness between lights I had time to absorb a remarkable story of outrageous fortune and despair.
Born in east London in 1910, Mr Greenman had British parents but a Dutch grandparent on his father's side. With his wife, Esther, he settled in Rotterdam in the 1930s and worked as an antiquarian bookseller, travelling regularlybetween the Netherlands and Britain on business. On one trip to London in 1938 he saw people digging trenches in the street and queuing for gas masks and heard talk of war. He hurried back to Rotterdam intending to collect his wife and return to England. But he was assured by the British consulate his family would be notified to leave with diplomatic staff if war broke out. He decided to stay.
In 1940 the Nazis invaded the Netherlands. By this time Leon and Esther's first child, Barney, had been born. Valuing his identity, Leon had entrusted his British passport, family documents and pound;758 life savings to non-Jewish Dutch friends. But when he went to retrieve them he was told they no longer held them. Evidence of his family's British nationality had been burned.
By this time the British consulate had been abandoned. With no papers and no money, Mr Greenman was on his own. Suddenly he was thrown into a race against time: to be recognised as a British citizen and secure new papers before he and his family were deported as Jews. The papers never arrived.
Today Leon Greenman's testimony makes him many friends but some hateful enemies too. At the end of a lecture, members of the audience often come and shake his hand. But his lectures are never openly publicised for fear of disruption and violence from neo-Nazi groups wanting to discredit him and his testimony. Right-wing websites denying him and the Holocaust are easy to find.
Intimidation forced him to put security wire in the windows of his home after neo-Nazis entered and smashed up his house in 1994. Last Christmas he received cards covered with anti-Jewish obscenities and swastikas and containing poisonous threats.
"They say they will make a lampshade or a piece of soap out of me. But I do not want to give in to them. I have had wire put on windows and extra locks on my door. I am still surviving. I still get rings on my door and phone and there is no one there."
Mr Greenman's life mission is to educate a new generation about the Holocaust. It is his way of fighting the racism that killed 70 members of his close and extended family.
"I have lost everything. My wife, child, family and friends. Now I have no one. I am still making good a promise I made to God in 1943. My message is for young people to enter this world and make it a better place - to make a more peaceful life."
Leon Greenman's book An Englishman at Auschwitz is published by Vallentine Mitchell, pound;11.95.For information about the Jewish Museum: www.jewishmuseum.org.uk. Holocaust Memorial Day is on January 27
THE PERSONAL TOUCH
Last week, Tanya Long from Gowerton secondary school in Swansea made her third trip to visit Leon Greenman and his permanent one-man exhibition at the Jewish Museum. She travelled to London with 39 Year 10 pupils who are studying the Holocaust as part of their GCSE religious studies course.
"The day is useful for students to form their own opinions - and Leon's talk adds the personal touch," she says. "His story has a big impact on students." Listening to a survivor of some of the 20th century's darkest days clearly affects his audience. "It was so sad I wanted to cry," says one after hearing how Mr Greenman was separated from his wife and child on arriving at Birkenau.
His memories are charged with emotion especially for a Year 10 audience; vows of love made to Esther ("Else") before they were arrested; the arrival of documents 15 minutes too late to save them from deportation; and the death march to Buchenwald.
Among the exhibits are his son's clothes, toys "and even the baby's beautiful curls". One pupil says the personal items "made me shiver. The uniform - it was so thin and pathetic. It was all he wore in the cold of Poland." All who saw the tattooed number on his forearm were shocked.
Ms Long says her students were depressed to learn how Mr Greenman was still persecuted by neo-Nazis. But she adds: "Most of the pupils come away from the day feeling privileged to have been able to hear a survivor speak."