This is the final film of Robert Donat, who died during its making. In the scene in which he is saying goodbye to Gladys as the elders prepare to take their leave of the city, he says, as though he was prophesying his death, "I fear we shall never see each other again."
The real Gladys Aylward (1902-1970), born in London, was a former domestic turned missionary in China, best known for her work with children. She became a Chinese citizen in 1936. Four years later, despite being in ill health herself, she shepherded more than 100 children over the mountains to safety at the height of the Sino-Japanese war. In 1958, the year this film was released, she founded a children's home in Taiwan, which she continued to run until her death. Known in China as "Ai-weh-deh", or "Virtous One", she continues to be regarded as a national heroine.
The real Gladys Aylward was reportedly embarrassed at the romantic part of the film. She did fall in love with a Chinese soldier, but they never married, and their affair was very brief.
Robert Donat had suffered from chronic asthma all his life, and had turned down many offers because of this. He worked very little during the 1950s, and it is reputed that he was almost penniless when he accepted the role in this film. After he died, he left just £25,000 in his will--which was his salary from this film.
The outdoor scenes were filmed almost entirely in North Wales, near where The Prisoner (1967) was set. Some studio work was done in England, meaning the entire film was made in the West using Chinese extras. Most of the children in the film were Chinese children from Liverpool, which has one of the oldest Chinese communities in Europe.