"On a trip like this [to Nanjing] you see destruction all around," Sindberg wrote in a letter published on March 6, 1938 in the newspaper Aarhus Stiftstidende. "All villages are torched. All cattle and poultry are taken. Wherever you look, lie the corpses of killed peasants and Chinese soldiers, serving as food for stray dogs and wild animals."

A quick tour of the museum's artifacts was visibly moving for Petersen, who came to China as Denmark's ambassador when the book project was nearly complete last year.

"Today we commemorate Sindberg in China at the very place where the Chinese-Japanese war started," he said, referring to the July 7, 1937 attack at the Marco Polo Bridge outside the modern capital. The Japanese invasion of China targeted Beijing, Shanghai and ultimately Nanjing, the capital at that time.

Dai said that while Sindberg's actions made him a guardian angel in the eyes of Nanjing residents, among whom he was fondly referred as "Sir Xin of Denmark", as a journalist he was compelled by the story of a real man with flaws behind the heroic history.

"This was a person, not a god," Dai said. Courageous but not easy to work or live with, Sindberg earlier had been arrested for fighting on a ship and also joined the French Foreign Legion, where he expanded both his skills and his reputation for toughness.

"It adds to the credibility of Dai's book that the author is discussing the problem of Sindberg's complex personality," Petersen said, noting that his countryman had drawn a good salary while working for the cement-maker during the crisis.

After 107 days of siege, the frustrated Japanese pressured the company to send Sindberg out of China.

"He had a really hot temper, but he would give away the trousers he wore, to defend what he cared about," said Sindberg's 80-year-old sister Bitten Stenvig Andersen, who grew misty-eyed at a celebration of her brother's actual birthday, Feb 19, at his hometown of Aarhus.

Dignitaries attending included the Chinese ambassador to Denmark, Xie Hangsheng, and the vice-mayor of Aarhus, Rabih Azad-Ahmad.

"As a Dane and a member of the City Council, I am very proud to know that a fellow Dane from Aarhus found the courage to stand up against the Japanese occupation forces, and by doing so, saved the lives of thousands of Chinese," Azad-Ahmad told Xinhua.

The 100th anniversary commemorations began the week before in Nanjing, with a ribbon-cutting ceremony for a Sindberg exhibition at Nanjing Civil Museum on the War of Chinese People's Resistance Against Japanese Aggression.

Su Guobao, a 85-year-old villager helped by Sindberg who attended the event, was only 12 when he met the Dane. Sindberg gave him one silver dollar, and according to Su, his whole family survived, thanks to Sindberg's help.