1947

Though the exact dates were disputed, it was most commonly accepted that 1947 was the year in which the Cold War started, lasting until 1991. (PROSE: A History of Humankind)

A Nedenah spacecraft crashed in Roswell, New Mexico. (PROSE: The Devil Goblins from Neptune)

On 13 June, another spacecraft, piloted by alien ambassador Seruba Velak, also crash landed in the vicinity of Roswell. She was taken prisoner by the US government and held in captivity in Area 51 for the next eleven years until being freed by the Tenth Doctor and her husband Rivesh Mantilax in 1958. (TV: Dreamland)

The technology from one of the above crashes ended up in the hands of Henry van Statten decades later. He used it to develop broadband internet. (TV: Dalek)

The Tenth Doctor and Donna Noble arrived in Calcutta, British India where they met Mohandas Gandhi. (PROSE: Ghosts of India) India gained dominion status that same year. (PROSE: All-Consuming Fire)

On 17 August, Pakistan declared independence from India in what would become known as the Partition of India. The Thirteenth Doctor, Ryan Sinclair, Yasmin Khan and Graham O'Brien visited India and Pakistan on this date and listened to the partition being announced on the radio. (TV: Demons of the Punjab) On 18 August, the first wedding in Pakistan was held, between the Muslim Umbreen and the Hindu Prem. However, Prem was later killed by his brother Manish for marrying someone from another religion. (TV: Demons of the Punjab)

Undated events
The Second Doctor recalled either participating in or observing an alien autopsy, which was recorded, in Roswell during this year. The alien in question was presumably one of the victims of the crash of the Nedenah spacecraft. (PROSE: The Wheel of Ice)

The Second Doctor, Ben Jackson and Polly Wright arrived in Los Angeles and assisted the police in a murder investigation. (PROSE: Dying in the Sun)

British occultist Aleister Crowley faked his own death in Hastings as part of his recruitment by the Americans into the Golgotha Project. (PROSE: Heart of TARDIS)

The First Doctor and Dodo Chaplet visited Scrabster Harbour. (AUDIO: Masters of Earth)

Kenneth James Valentine joined that Cardiff Borough Police. (PROSE: Trace Memory)

According to the Twelfth Doctor's sonic sunglasses, Secretary General of the United Nations, who held this position in 2017, was born either in 1946 or in 1947. (TV: The Pyramid at the End of the World)