A letter sent from Mao Zedong to future British prime minister Clement Attlee is to cross the block at Sotheby's London.
It's valued at £100,000-150,000 ($152,650-228,975).
The letter dates to November 1, 1937 and appeals to Britain for support in the aftermath of the Japanese invasion.
Mao writes: "We know that the great majority of the British people stand firmly for peace and democracy…
"The Chinese people, like the people of Spain, stand now in the vanguard of the International Peace Front. Our Party and our Army are playing their part in that struggle.
"We are fighting with the whole Chinese people against an enemy that has deliberately turned against peace and the welfare of humanity."
While Attlee was unable to provide much practical help, he was clearly moved by the plight of the Chinese and was among the first to recognise the formation of the People's Republic of China in 1950.
He went on to meet with Mao in 1954, becoming one of the first western politicians to do so.
Mao was encouraged to write to Attlee by James Bertram, a journalist from New Zealand. Bertram crossed the Japanese lines to interview Mao and was rewarded with a candid audience.
Bertram's letter to Attlee is included in the lot. Bertram writes: "I asked these people if they would send some message to the British people, and especially to the British Labour Party, of which I hope I may still consider myself a member…
"…I was only too glad to do it, because I believe so firmly that international cooperation, & what still survives of the principle of 'collective security', is at the last gasp of its latest hour."
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