1961

"From start to finish", the year 1961 was noted by the War Doctor to be in flux. This was partly the reason the Time Lords installed a quantum shield to protect Earth against potential Dalek incursions during the Last Great Time War. Nevertheless, the Dalek Time Strategist enacted a plot to break through the shield using a human agent whom was sent to East Berlin with a Shadow Vortex, proceeding to exterminate all life in a bid to disrupt and ultimately wipe out the Doctor's existence through the elimination of his Earth allies. The resulting invasion was averted by the War Doctor, who shifted its events to an alternate timeline where Lara was banished. (AUDIO: The Shadow Vortex)

On 12 April, Yuri Gagarin of the Soviet Union became the first human to travel into space, at least officially. (AUDIO: Thin Ice)

UNIT's predecessor, Great Britain's Intrusion Countermeasures Group, was formed. Its leader, Group Captain Ian Gilmore, began training his men. (PROSE: Who Killed Kennedy)

Peter Tracey was born. (TV: A Girl's Best Friend)

Therése Gavalle was born in Lyon, France. (PROSE: Instruments of Darkness)

Allison Williams and Julian St. Stephen started dating. (AUDIO: Artificial Intelligence)

The Beatles gave their first show at the Cavern Club. (COMIC: What He Wants...)

Alternative timeline
In an alternative timeline in which Nazi Germany won World War II as a result of the Seventh Doctor and Ace accidentally leaving laser technology in Colditz Castle in October 1944, the Führer Adolf Hitler died at the age of 71 or 72. Prior to his death, he had stockpiled a large number of alien artefacts, including the TARDIS, but had kept them contained because he feared the implications of intelligence superior to humans. (AUDIO: Klein's Story)

Using the Shadow Vortex, the Daleks broke through the quantum shield protecting Earth. Arriving in East Berlin in 1961, the Daleks proceeded to exterminate all life on the planet. The timeline was reversed, however, through the intervention of the War Doctor, resulting in this outcome being superseded while still existing as an alternate reality. Lara Zannis was banished to this alternate timeline once the paradox shield protecting her broke. Meanwhile, as history resumed its intended course, several individuals in East Berlin remembered the attack due to being in the "eye of the storm". (AUDIO: The Shadow Vortex)