WE may not know his name now but in the 1930s Dr Janusz Korczak , a Pole, was very big in Europe. The Polish Government has declared 2012 the Year of Janusz Korczak.

Confessions of a Butterfly - The Key Theatre, Peterborough until Saturday, August 18 and at The Lion and the Unicorn in Kentish Town, London from September 10 to 29.

Review by ANGELA SINGER.

WE may not know his name now but in the 1930s Dr Janusz Korczak , a Pole, was very big in Europe. The Polish Government has declared 2012 the Year of Janusz Korczak. It's 70 years since he died.

Korczak, a jovial writer and paediatrician who ran two orphanages in Warsaw, one for Catholic and one for Jewish children had revolutionary ideas about childcare. He did not believe in corporal punishment and his orphanages had a "court" system where everyone, including the staff, could be challenged.

He was a huge, prime time celebrity in Poland and had a show on Polish State Radio every Friday night. He wrote for adults as well as children. His best known book is King Matt, a classic Polish children's story.

But Korczak was a Jew. He had changed his name from Henryk Goldschmidt in his 20s - some 40 years before the Nazis marched into Poland - because he feared he wouldn't get a play published under a Jewish name.

By 1940, he and 200 children in his Jewish orphanage had been forced into the Warsaw Ghetto. In August, 1942, the SS sent them (among 4,000 other children and 2,000 adults in that part of the ghetto) to the death camps. Korczak was seen leading the column of his children through the streets, but he led them out of the orphanage in their best clothes, he was telling them jokes and they were singing. He didn't want them to be afraid. He knew what was going to happen. He had considered giving everyone morphine.

Jonathan Salt, a former teacher and a director of the accoladed and Edinburgh starred St Ives Youth Theatre in Cambridgeshire, has written a one-man play based on the diaries of Korczak. This is Korczak's life up until that day in August, recreating the last months that he and the children spent in the Ghetto (Korczak went out every day with a sack begging for food)...and looking back on the doctor's life.

The immaculate writing lovingly recreates the man, as a human being who made mistakes - like all parents do. It evokes the atmosphere of the ghetto and the lives of the children, their quarrels, their play, their fears. It is gentle, funny, endearing, yet chilling. You imagine the children sitting on the floor in front of him, listening to a story he tells about disability, how everyone has a part to play, and another to explain death, telling them why they must not be afraid....because at the end of their journey, they will be free.

Salt has set himself - as the actor - a Herculean task. Korczak has to be humourous, entertaining, yet outraged at what is happening and at the same time, dying. He was in poor health, his death was a race between the Nazis and disease....but keeping up the spirits of the children and dealing with the day to day practicalities has to displace all that. Salt, like Korczak is a great story-teller and his performance will through the run get even stronger and more nuanced.

This is a fine production with inspired staging and involvement from children and young people across Cambridgeshire, who have all learned the story. Salt, like Korczak, is an educator. The set was built by young offenders at Littlehey Prison. The violin pieces, played in the orphanage by a child who at nine had been recognised as a prodigy by the Warsaw Conservatoire, is played by Tom Pickard, a pupil at King's College, School, Cambridge, and the song the Ghetto children sang as they were led away to die is sung in Polish by 40 pupils at Wheatfields Primary School in St Ives.

Even on the verge of death, life is about the day to day...and to Korczak people are just people... He looks out of the building down to the street and says: "My bald head in the window - what a splendid target, a bit different from the children drawing all over it.

"Why is he (the German soldier) standing and looking on so calmly? He has no orders to shoot...Perhaps he was a village teacher in civilian life, or a notary, a street sweeper in Leipzig, a waiter in Cologne? He may have arrived only yesterday from far away."

For Korczak and for Jonathan Salt, horror comes from indifference to others.