1834年

In 1834, the Star Chamber attacked the Eleven-Day Empire. (PROSE: The Book of the War)

The Thirteenth Doctor and Ada Lovelace were transported from the Kasaavin realm to an invention exhibition in London 1834, where they encountered the Master. Ada took the Doctor to the residence of polymath Charles Babbage, where the Doctor summoned a Kasaavin, hoping to return to the 21st century. Ada grabbed the Doctor's hand at the last moment and they accidentally travelled to Paris in 1943 instead. (TV: Spyfall)