While these events are considered aprocryphal in our own reality, the date in confirmed by the Doctor. In Constantinople, the Doctor carves a challenges the ancient evil known as Fenric to solve a chess problem. When Fenric fails, the Doctor is able to trap his essence in a flask, banishing Fenric to the Shadow Dimensions. The Roman Cult of Demnos is believed to die out at this time, although it will continue on in secret until at least the late 15th century. The Masque of Mandragora.
Exact date is conjecture.
On Skaro, the radiation level near a Dalek city is measured at 96 units. On the planet Skaro, the 1st Doctor, Susan, Barbara and Ian encounter the Daleks, and help a group of Thals invade their City and immobilize them. I am using the date from James Armstrong's chronology. A Zygon spaceship crashes in Loch Ness, Scotland. Terror of the Zygons.