Who was Peter Nielsen based on in Number the Stars?

Peter Nielsen Was part of the Resistance. He was engage with Lise Johannes how die 2 weeks before their wedding she was also part of the Resistance.Peter helped the Roses escape to Sweden. Then he die because the NAZI found him and Killed him. He wrote a letter 1 day before his death and asked to be Buried next to Lise. But the NAZI buried him were he die. Peter Nielsen die very young. He was a brave young man who fought for Denmark Jews.