He often bought badly needed medicine for wounded fighters and he also purchased vital telegraph components for the Chinese army.

After spending three years fighting and living in the Jinchaji base, Lindsay and his wife arrived in Yan'an in Shaanxi province in 1944 and helped the headquarters of the Eighth Route Army there to fix its telecommunication equipment.

They stayed for 18 months in Yan'an, and after the victory in the War of Resistance Against Japanese Aggression, they decided to return to the United Kingdom to visit their parents, and went via the United States in 1945.

Lindsay stayed for eight years in China, and his two children were born in conflict zones.

He made only a few low-profile visits to China after the war, mostly in the role of an economist and scholar on international relations.

"Lindsay is an internationalist who helped Chinese people through their most difficult time, and recorded their hardship and bravery," says Yan, adding that Lindsay introduced the philosophy of Keynesian economics to China and helped China to fight against Japanese aggression.

"He has contributed greatly to the friendship between China and the UK," he says.

Xie Dehui, from the city of Lyuliang in Shanxi, was impressed after he visited the Lindsay and Li Xiaoli Memorial Hall. It reminded him of the stories he had heard of those extraordinary times and how that era gave rise to incredible and heroic feats.

"As descendants of the region, we should learn from these heroes, in that we need to carry on their spirit of internationalism. And we should be dedicated and devoted to our own jobs, to work hard for the revitalization of the great Chinese civilization.