Mao Zedong

Mao Tse-Tung was a Chairman of China in the 20th century. During the preparations for the World Peace Conference, the Third Doctor mentioned to the Chinese delegate Fu Peng that he remembered having a conversation in Hokkien with Mao, at which time the Chairman allowed the Doctor to call him by his personal name, "Tse-Tung". (TV: The Mind of Evil)

Behind the scenes

 * The fact that the Doctor suggests he spoke Hokkien with Mao suggests a difference between the real world and the DWU. In real life, Mao did not speak Hokkien, as he came from deep within rural, far away from the reach of Hokkien.
 * Mao Tse-Tung is referred to in the present tense, implying that the story is set at the time of broadcast — i.e. 1971 — rather than the five years into the future where the UNIT-related Doctor Who stories are often said to take place (Mao died in 1976).